db_test.go

// Copyright 2015 PingCAP, Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// See the License for the specific language governing permissions and
// limitations under the License.

package ddl_test

import (
	"context"
	"fmt"
	"io"
	"math"
	"math/rand"
	"strconv"
	"strings"
	"sync"
	"sync/atomic"
	"time"

	. "github.com/pingcap/check"
	"github.com/pingcap/errors"
	"github.com/pingcap/failpoint"
	"github.com/pingcap/parser/model"
	"github.com/pingcap/parser/mysql"
	"github.com/pingcap/parser/terror"
	"github.com/pingcap/tidb/config"
	"github.com/pingcap/tidb/ddl"
	testddlutil "github.com/pingcap/tidb/ddl/testutil"
	"github.com/pingcap/tidb/domain"
	"github.com/pingcap/tidb/infoschema"
	"github.com/pingcap/tidb/kv"
	"github.com/pingcap/tidb/meta/autoid"
	"github.com/pingcap/tidb/session"
	"github.com/pingcap/tidb/sessionctx"
	"github.com/pingcap/tidb/store/mockstore"
	"github.com/pingcap/tidb/store/mockstore/mocktikv"
	"github.com/pingcap/tidb/table"
	"github.com/pingcap/tidb/table/tables"
	"github.com/pingcap/tidb/tablecodec"
	"github.com/pingcap/tidb/types"
	"github.com/pingcap/tidb/util/admin"
	"github.com/pingcap/tidb/util/israce"
	"github.com/pingcap/tidb/util/mock"
	"github.com/pingcap/tidb/util/testkit"
	"github.com/pingcap/tidb/util/testutil"
)

const (
	// waitForCleanDataRound indicates how many times should we check data is cleaned or not.
	waitForCleanDataRound = 150
	// waitForCleanDataInterval is a min duration between 2 check for data clean.
	waitForCleanDataInterval = time.Millisecond * 100
)

var _ = Suite(&testDBSuite1{&testDBSuite{}})
var _ = Suite(&testDBSuite2{&testDBSuite{}})
var _ = Suite(&testDBSuite3{&testDBSuite{}})
var _ = Suite(&testDBSuite4{&testDBSuite{}})
var _ = Suite(&testDBSuite5{&testDBSuite{}})

const defaultBatchSize = 1024

type testDBSuite struct {
	cluster    *mocktikv.Cluster
	mvccStore  mocktikv.MVCCStore
	store      kv.Storage
	dom        *domain.Domain
	schemaName string
	tk         *testkit.TestKit
	s          session.Session
	lease      time.Duration
	autoIDStep int64
}

func setUpSuite(s *testDBSuite, c *C) {
	var err error

	s.lease = 100 * time.Millisecond
	session.SetSchemaLease(s.lease)
	session.DisableStats4Test()
	s.schemaName = "test_db"
	s.autoIDStep = autoid.GetStep()
	ddl.WaitTimeWhenErrorOccured = 0

	s.cluster = mocktikv.NewCluster()
	mocktikv.BootstrapWithSingleStore(s.cluster)
	s.mvccStore = mocktikv.MustNewMVCCStore()
	s.store, err = mockstore.NewMockTikvStore(
		mockstore.WithCluster(s.cluster),
		mockstore.WithMVCCStore(s.mvccStore),
	)
	c.Assert(err, IsNil)

	s.dom, err = session.BootstrapSession(s.store)
	c.Assert(err, IsNil)
	s.s, err = session.CreateSession4Test(s.store)
	c.Assert(err, IsNil)

	_, err = s.s.Execute(context.Background(), "create database test_db")
	c.Assert(err, IsNil)

	s.tk = testkit.NewTestKit(c, s.store)
}

func tearDownSuite(s *testDBSuite, c *C) {
	s.s.Execute(context.Background(), "drop database if exists test_db")
	s.s.Close()
	s.dom.Close()
	s.store.Close()
}

func (s *testDBSuite) SetUpSuite(c *C) {
	setUpSuite(s, c)
}

func (s *testDBSuite) TearDownSuite(c *C) {
	tearDownSuite(s, c)
}

type testDBSuite1 struct{ *testDBSuite }
type testDBSuite2 struct{ *testDBSuite }
type testDBSuite3 struct{ *testDBSuite }
type testDBSuite4 struct{ *testDBSuite }
type testDBSuite5 struct{ *testDBSuite }

func (s *testDBSuite4) TestAddIndexWithPK(c *C) {
	s.tk = testkit.NewTestKit(c, s.store)
	s.tk.MustExec("use " + s.schemaName)

	s.tk.MustExec("create table test_add_index_with_pk(a int not null, b int not null default '0', primary key(a))")
	s.tk.MustExec("insert into test_add_index_with_pk values(1, 2)")
	s.tk.MustExec("alter table test_add_index_with_pk add index idx (a)")
	s.tk.MustQuery("select a from test_add_index_with_pk").Check(testkit.Rows("1"))
	s.tk.MustExec("insert into test_add_index_with_pk values(2, 2)")
	s.tk.MustExec("alter table test_add_index_with_pk add index idx1 (a, b)")
	s.tk.MustQuery("select * from test_add_index_with_pk").Check(testkit.Rows("1 2", "2 2"))
	s.tk.MustExec("create table test_add_index_with_pk1(a int not null, b int not null default '0', c int, d int, primary key(c))")
	s.tk.MustExec("insert into test_add_index_with_pk1 values(1, 1, 1, 1)")
	s.tk.MustExec("alter table test_add_index_with_pk1 add index idx (c)")
	s.tk.MustExec("insert into test_add_index_with_pk1 values(2, 2, 2, 2)")
	s.tk.MustQuery("select * from test_add_index_with_pk1").Check(testkit.Rows("1 1 1 1", "2 2 2 2"))
	s.tk.MustExec("create table test_add_index_with_pk2(a int not null, b int not null default '0', c int unsigned, d int, primary key(c))")
	s.tk.MustExec("insert into test_add_index_with_pk2 values(1, 1, 1, 1)")
	s.tk.MustExec("alter table test_add_index_with_pk2 add index idx (c)")
	s.tk.MustExec("insert into test_add_index_with_pk2 values(2, 2, 2, 2)")
	s.tk.MustQuery("select * from test_add_index_with_pk2").Check(testkit.Rows("1 1 1 1", "2 2 2 2"))
}

func (s *testDBSuite1) TestRenameIndex(c *C) {
	s.tk = testkit.NewTestKit(c, s.store)
	s.tk.MustExec("use " + s.schemaName)
	s.tk.MustExec("create table t (pk int primary key, c int default 1, c1 int default 1, unique key k1(c), key k2(c1))")

	// Test rename success
	s.tk.MustExec("alter table t rename index k1 to k3")
	s.tk.MustExec("admin check index t k3")

	// Test rename to the same name
	s.tk.MustExec("alter table t rename index k3 to k3")
	s.tk.MustExec("admin check index t k3")

	// Test rename on non-exists keys
	s.tk.MustGetErrCode("alter table t rename index x to x", mysql.ErrKeyDoesNotExist)

	// Test rename on already-exists keys
	s.tk.MustGetErrCode("alter table t rename index k3 to k2", mysql.ErrDupKeyName)

	s.tk.MustExec("alter table t rename index k2 to K2")
	s.tk.MustGetErrCode("alter table t rename key k3 to K2", mysql.ErrDupKeyName)
}

func testGetTableByName(c *C, ctx sessionctx.Context, db, table string) table.Table {
	dom := domain.GetDomain(ctx)
	// Make sure the table schema is the new schema.
	err := dom.Reload()
	c.Assert(err, IsNil)
	tbl, err := dom.InfoSchema().TableByName(model.NewCIStr(db), model.NewCIStr(table))
	c.Assert(err, IsNil)
	return tbl
}

func (s *testDBSuite) testGetTable(c *C, name string) table.Table {
	ctx := s.s.(sessionctx.Context)
	return testGetTableByName(c, ctx, s.schemaName, name)
}

func (s *testDBSuite) testGetDB(c *C, dbName string) *model.DBInfo {
	ctx := s.s.(sessionctx.Context)
	dom := domain.GetDomain(ctx)
	// Make sure the table schema is the new schema.
	err := dom.Reload()
	c.Assert(err, IsNil)
	db, ok := dom.InfoSchema().SchemaByName(model.NewCIStr(dbName))
	c.Assert(ok, IsTrue)
	return db
}

func backgroundExec(s kv.Storage, sql string, done chan error) {
	se, err := session.CreateSession4Test(s)
	if err != nil {
		done <- errors.Trace(err)
		return
	}
	defer se.Close()
	_, err = se.Execute(context.Background(), "use test_db")
	if err != nil {
		done <- errors.Trace(err)
		return
	}
	_, err = se.Execute(context.Background(), sql)
	done <- errors.Trace(err)
}

// TestAddPrimaryKeyRollback1 is used to test scenarios that will roll back when a duplicate primary key is encountered.
func (s *testDBSuite5) TestAddPrimaryKeyRollback1(c *C) {
	hasNullValsInKey := false
	idxName := "PRIMARY"
	addIdxSQL := "alter table t1 add primary key c3_index (c3);"
	errMsg := "[kv:1062]Duplicate entry '' for key 'PRIMARY'"
	testAddIndexRollback(c, s.store, s.lease, idxName, addIdxSQL, errMsg, hasNullValsInKey)
}

// TestAddPrimaryKeyRollback2 is used to test scenarios that will roll back when a null primary key is encountered.
func (s *testDBSuite1) TestAddPrimaryKeyRollback2(c *C) {
	hasNullValsInKey := true
	idxName := "PRIMARY"
	addIdxSQL := "alter table t1 add primary key c3_index (c3);"
	errMsg := "[ddl:1138]Invalid use of NULL value"
	testAddIndexRollback(c, s.store, s.lease, idxName, addIdxSQL, errMsg, hasNullValsInKey)
}

func (s *testDBSuite2) TestAddUniqueIndexRollback(c *C) {
	hasNullValsInKey := false
	idxName := "c3_index"
	addIdxSQL := "create unique index c3_index on t1 (c3)"
	errMsg := "[kv:1062]Duplicate entry '' for key 'c3_index'"
	testAddIndexRollback(c, s.store, s.lease, idxName, addIdxSQL, errMsg, hasNullValsInKey)
}

func batchInsert(tk *testkit.TestKit, tbl string, start, end int) {
	dml := fmt.Sprintf("insert into %s values", tbl)
	for i := start; i < end; i++ {
		dml += fmt.Sprintf("(%d, %d, %d)", i, i, i)
		if i != end-1 {
			dml += ","
		}
	}
	tk.MustExec(dml)
}

func testAddIndexRollback(c *C, store kv.Storage, lease time.Duration,
	idxName, addIdxSQL, errMsg string, hasNullValsInKey bool) {
	tk := testkit.NewTestKit(c, store)
	tk.MustExec("use test_db")
	tk.MustExec("drop table if exists t1")
	tk.MustExec("create table t1 (c1 int, c2 int, c3 int, unique key(c1))")
	// defaultBatchSize is equal to ddl.defaultBatchSize
	base := defaultBatchSize * 2
	count := base
	// add some rows
	batchInsert(tk, "t1", 0, count)
	// add some null rows
	if hasNullValsInKey {
		for i := count - 10; i < count; i++ {
			tk.MustExec("insert into t1 values (?, ?, null)", i+10, i)
		}
	} else {
		// add some duplicate rows
		for i := count - 10; i < count; i++ {
			tk.MustExec("insert into t1 values (?, ?, ?)", i+10, i, i)
		}
	}

	done := make(chan error, 1)
	go backgroundExec(store, addIdxSQL, done)

	times := 0
	ticker := time.NewTicker(lease / 2)
	defer ticker.Stop()
LOOP:
	for {
		select {
		case err := <-done:
			c.Assert(err, NotNil)
			c.Assert(err.Error(), Equals, errMsg, Commentf("err:%v", err))
			break LOOP
		case <-ticker.C:
			if times >= 10 {
				break
			}
			step := 5
			// delete some rows, and add some data
			for i := count; i < count+step; i++ {
				n := rand.Intn(count)
				tk.MustExec("delete from t1 where c1 = ?", n)
				tk.MustExec("insert into t1 values (?, ?, ?)", i+10, i, i)
			}
			count += step
			times++
		}
	}

	ctx := tk.Se.(sessionctx.Context)
	t := testGetTableByName(c, ctx, "test_db", "t1")
	for _, tidx := range t.Indices() {
		c.Assert(strings.EqualFold(tidx.Meta().Name.L, idxName), IsFalse)
	}

	// delete duplicated/null rows, then add index
	for i := base - 10; i < base; i++ {
		tk.MustExec("delete from t1 where c1 = ?", i+10)
	}
	sessionExec(c, store, addIdxSQL)
	tk.MustExec("drop table t1")
}

func (s *testDBSuite5) TestCancelAddPrimaryKey(c *C) {
	idxName := "primary"
	addIdxSQL := "alter table t1 add primary key idx_c2 (c2);"
	testCancelAddIndex(c, s.store, s.dom.DDL(), s.lease, idxName, addIdxSQL, "")

	// Check the column's flag when the "add primary key" failed.
	tk := testkit.NewTestKit(c, s.store)
	tk.MustExec("use test_db")
	ctx := tk.Se.(sessionctx.Context)
	c.Assert(ctx.NewTxn(context.Background()), IsNil)
	t := testGetTableByName(c, ctx, "test_db", "t1")
	col1Flag := t.Cols()[1].Flag
	c.Assert(!mysql.HasNotNullFlag(col1Flag) && !mysql.HasPreventNullInsertFlag(col1Flag) && mysql.HasUnsignedFlag(col1Flag), IsTrue)
	tk.MustExec("drop table t1")
}

func (s *testDBSuite3) TestCancelAddIndex(c *C) {
	idxName := "c3_index "
	addIdxSQL := "create unique index c3_index on t1 (c3)"
	testCancelAddIndex(c, s.store, s.dom.DDL(), s.lease, idxName, addIdxSQL, "")

	tk := testkit.NewTestKit(c, s.store)
	tk.MustExec("use test_db")
	tk.MustExec("drop table t1")
}

func testCancelAddIndex(c *C, store kv.Storage, d ddl.DDL, lease time.Duration, idxName, addIdxSQL, sqlModeSQL string) {
	tk := testkit.NewTestKit(c, store)
	tk.MustExec("use test_db")
	tk.MustExec("drop table if exists t1")
	tk.MustExec("create table t1 (c1 int, c2 int unsigned, c3 int, unique key(c1))")
	// defaultBatchSize is equal to ddl.defaultBatchSize
	count := defaultBatchSize * 2
	start := 0
	// add some rows
	if len(sqlModeSQL) != 0 {
		// Insert some null values.
		tk.MustExec(sqlModeSQL)
		tk.MustExec("insert into t1 set c1 = ?", 0)
		tk.MustExec("insert into t1 set c2 = ?", 1)
		tk.MustExec("insert into t1 set c3 = ?", 2)
		start = 3
	}
	for i := start; i < count; i++ {
		tk.MustExec("insert into t1 values (?, ?, ?)", i, i, i)
	}

	var c3IdxInfo *model.IndexInfo
	hook := &ddl.TestDDLCallback{}
	originBatchSize := tk.MustQuery("select @@global.tidb_ddl_reorg_batch_size")
	// Set batch size to lower try to slow down add-index reorganization, This if for hook to cancel this ddl job.
	tk.MustExec("set @@global.tidb_ddl_reorg_batch_size = 32")
	defer tk.MustExec(fmt.Sprintf("set @@global.tidb_ddl_reorg_batch_size = %v", originBatchSize.Rows()[0][0]))
	// let hook.OnJobUpdatedExported has chance to cancel the job.
	// the hook.OnJobUpdatedExported is called when the job is updated, runReorgJob will wait ddl.ReorgWaitTimeout, then return the ddl.runDDLJob.
	// After that ddl call d.hook.OnJobUpdated(job), so that we can canceled the job in this test case.
	var checkErr error
	ctx := tk.Se.(sessionctx.Context)
	hook.OnJobUpdatedExported, c3IdxInfo, checkErr = backgroundExecOnJobUpdatedExported(c, store, ctx, hook, idxName)
	originalHook := d.GetHook()
	d.(ddl.DDLForTest).SetHook(hook)
	done := make(chan error, 1)
	go backgroundExec(store, addIdxSQL, done)

	times := 0
	ticker := time.NewTicker(lease / 2)
	defer ticker.Stop()
LOOP:
	for {
		select {
		case err := <-done:
			c.Assert(checkErr, IsNil)
			c.Assert(err, NotNil)
			c.Assert(err.Error(), Equals, "[ddl:8214]Cancelled DDL job")
			break LOOP
		case <-ticker.C:
			if times >= 10 {
				break
			}
			step := 5
			// delete some rows, and add some data
			for i := count; i < count+step; i++ {
				n := rand.Intn(count)
				tk.MustExec("delete from t1 where c1 = ?", n)
				tk.MustExec("insert into t1 values (?, ?, ?)", i+10, i, i)
			}
			count += step
			times++
		}
	}

	t := testGetTableByName(c, ctx, "test_db", "t1")
	for _, tidx := range t.Indices() {
		c.Assert(strings.EqualFold(tidx.Meta().Name.L, idxName), IsFalse)
	}

	idx := tables.NewIndex(t.Meta().ID, t.Meta(), c3IdxInfo)
	checkDelRangeDone(c, ctx, idx)
	d.(ddl.DDLForTest).SetHook(originalHook)
}

// TestCancelAddIndex1 tests canceling ddl job when the add index worker is not started.
func (s *testDBSuite4) TestCancelAddIndex1(c *C) {
	s.tk = testkit.NewTestKit(c, s.store)
	s.mustExec(c, "use test_db")
	s.mustExec(c, "drop table if exists t")
	s.mustExec(c, "create table t(c1 int, c2 int)")
	defer s.mustExec(c, "drop table t;")

	for i := 0; i < 50; i++ {
		s.mustExec(c, "insert into t values (?, ?)", i, i)
	}

	var checkErr error
	hook := &ddl.TestDDLCallback{}
	hook.OnJobRunBeforeExported = func(job *model.Job) {
		if job.Type == model.ActionAddIndex && job.State == model.JobStateRunning && job.SchemaState == model.StateWriteReorganization && job.SnapshotVer == 0 {
			jobIDs := []int64{job.ID}
			hookCtx := mock.NewContext()
			hookCtx.Store = s.store
			err := hookCtx.NewTxn(context.Background())
			if err != nil {
				checkErr = errors.Trace(err)
				return
			}
			txn, err := hookCtx.Txn(true)
			if err != nil {
				checkErr = errors.Trace(err)
				return
			}
			errs, err := admin.CancelJobs(txn, jobIDs)
			if err != nil {
				checkErr = errors.Trace(err)
				return
			}

			if errs[0] != nil {
				checkErr = errors.Trace(errs[0])
				return
			}

			checkErr = txn.Commit(context.Background())
		}
	}
	originalHook := s.dom.DDL().GetHook()
	s.dom.DDL().(ddl.DDLForTest).SetHook(hook)
	rs, err := s.tk.Exec("alter table t add index idx_c2(c2)")
	if rs != nil {
		rs.Close()
	}
	c.Assert(checkErr, IsNil)
	c.Assert(err, NotNil)
	c.Assert(err.Error(), Equals, "[ddl:8214]Cancelled DDL job")

	s.dom.DDL().(ddl.DDLForTest).SetHook(originalHook)
	t := s.testGetTable(c, "t")
	for _, idx := range t.Indices() {
		c.Assert(strings.EqualFold(idx.Meta().Name.L, "idx_c2"), IsFalse)
	}
	s.mustExec(c, "alter table t add index idx_c2(c2)")
	s.mustExec(c, "alter table t drop index idx_c2")
}

// TestCancelDropIndex tests cancel ddl job which type is drop primary key.
func (s *testDBSuite4) TestCancelDropPrimaryKey(c *C) {
	idxName := "primary"
	addIdxSQL := "alter table t add primary key idx_c2 (c2);"
	dropIdxSQL := "alter table t drop primary key;"
	testCancelDropIndex(c, s.store, s.dom.DDL(), idxName, addIdxSQL, dropIdxSQL)
}

// TestCancelDropIndex tests cancel ddl job which type is drop index.
func (s *testDBSuite5) TestCancelDropIndex(c *C) {
	idxName := "idx_c2"
	addIdxSQL := "alter table t add index idx_c2 (c2);"
	dropIdxSQL := "alter table t drop index idx_c2;"
	testCancelDropIndex(c, s.store, s.dom.DDL(), idxName, addIdxSQL, dropIdxSQL)
}

// testCancelDropIndex tests cancel ddl job which type is drop index.
func testCancelDropIndex(c *C, store kv.Storage, d ddl.DDL, idxName, addIdxSQL, dropIdxSQL string) {
	tk := testkit.NewTestKit(c, store)
	tk.MustExec("use test_db")
	tk.MustExec("drop table if exists t")
	tk.MustExec("create table t(c1 int, c2 int)")
	defer tk.MustExec("drop table t;")
	for i := 0; i < 5; i++ {
		tk.MustExec("insert into t values (?, ?)", i, i)
	}
	testCases := []struct {
		needAddIndex   bool
		jobState       model.JobState
		JobSchemaState model.SchemaState
		cancelSucc     bool
	}{
		// model.JobStateNone means the jobs is canceled before the first run.
		{true, model.JobStateNone, model.StateNone, true},
		{false, model.JobStateRunning, model.StateWriteOnly, true},
		{false, model.JobStateRunning, model.StateDeleteOnly, false},
		{true, model.JobStateRunning, model.StateDeleteReorganization, false},
	}
	var checkErr error
	hook := &ddl.TestDDLCallback{}
	var jobID int64
	testCase := &testCases[0]
	hook.OnJobRunBeforeExported = func(job *model.Job) {
		if (job.Type == model.ActionDropIndex || job.Type == model.ActionDropPrimaryKey) &&
			job.State == testCase.jobState && job.SchemaState == testCase.JobSchemaState {
			jobID = job.ID
			jobIDs := []int64{job.ID}
			hookCtx := mock.NewContext()
			hookCtx.Store = store
			err := hookCtx.NewTxn(context.TODO())
			if err != nil {
				checkErr = errors.Trace(err)
				return
			}
			txn, err := hookCtx.Txn(true)
			if err != nil {
				checkErr = errors.Trace(err)
				return
			}

			errs, err := admin.CancelJobs(txn, jobIDs)
			if err != nil {
				checkErr = errors.Trace(err)
				return
			}
			if errs[0] != nil {
				checkErr = errors.Trace(errs[0])
				return
			}
			checkErr = txn.Commit(context.Background())
		}
	}
	originalHook := d.GetHook()
	d.(ddl.DDLForTest).SetHook(hook)
	ctx := tk.Se.(sessionctx.Context)
	for i := range testCases {
		testCase = &testCases[i]
		if testCase.needAddIndex {
			tk.MustExec(addIdxSQL)
		}
		rs, err := tk.Exec(dropIdxSQL)
		if rs != nil {
			rs.Close()
		}
		t := testGetTableByName(c, ctx, "test_db", "t")
		indexInfo := t.Meta().FindIndexByName(idxName)
		if testCase.cancelSucc {
			c.Assert(checkErr, IsNil)
			c.Assert(err, NotNil)
			c.Assert(err.Error(), Equals, "[ddl:8214]Cancelled DDL job")
			c.Assert(indexInfo, NotNil)
			c.Assert(indexInfo.State, Equals, model.StatePublic)
		} else {
			err1 := admin.ErrCannotCancelDDLJob.GenWithStackByArgs(jobID)
			c.Assert(err, IsNil)
			c.Assert(checkErr, NotNil)
			c.Assert(checkErr.Error(), Equals, err1.Error())
			c.Assert(indexInfo, IsNil)
		}
	}
	d.(ddl.DDLForTest).SetHook(originalHook)
	tk.MustExec(addIdxSQL)
	tk.MustExec(dropIdxSQL)
}

// TestCancelTruncateTable tests cancel ddl job which type is truncate table.
func (s *testDBSuite5) TestCancelTruncateTable(c *C) {
	s.tk = testkit.NewTestKit(c, s.store)
	s.mustExec(c, "use test_db")
	s.mustExec(c, "create database if not exists test_truncate_table")
	s.mustExec(c, "drop table if exists t")
	s.mustExec(c, "create table t(c1 int, c2 int)")
	defer s.mustExec(c, "drop table t;")
	var checkErr error
	hook := &ddl.TestDDLCallback{}
	hook.OnJobRunBeforeExported = func(job *model.Job) {
		if job.Type == model.ActionTruncateTable && job.State == model.JobStateNone {
			jobIDs := []int64{job.ID}
			hookCtx := mock.NewContext()
			hookCtx.Store = s.store
			err := hookCtx.NewTxn(context.Background())
			if err != nil {
				checkErr = errors.Trace(err)
				return
			}
			txn, err := hookCtx.Txn(true)
			if err != nil {
				checkErr = errors.Trace(err)
				return
			}
			errs, err := admin.CancelJobs(txn, jobIDs)
			if err != nil {
				checkErr = errors.Trace(err)
				return
			}
			if errs[0] != nil {
				checkErr = errors.Trace(errs[0])
				return
			}
			checkErr = txn.Commit(context.Background())
		}
	}
	originalHook := s.dom.DDL().GetHook()
	s.dom.DDL().(ddl.DDLForTest).SetHook(hook)
	_, err := s.tk.Exec("truncate table t")
	c.Assert(checkErr, IsNil)
	c.Assert(err, NotNil)
	c.Assert(err.Error(), Equals, "[ddl:8214]Cancelled DDL job")
	s.dom.DDL().(ddl.DDLForTest).SetHook(originalHook)
}

// TestCancelRenameIndex tests cancel ddl job which type is rename index.
func (s *testDBSuite1) TestCancelRenameIndex(c *C) {
	s.tk = testkit.NewTestKit(c, s.store)
	s.mustExec(c, "use test_db")
	s.mustExec(c, "create database if not exists test_rename_index")
	s.mustExec(c, "drop table if exists t")
	s.mustExec(c, "create table t(c1 int, c2 int)")
	defer s.mustExec(c, "drop table t;")
	for i := 0; i < 100; i++ {
		s.mustExec(c, "insert into t values (?, ?)", i, i)
	}
	s.mustExec(c, "alter table t add index idx_c2(c2)")
	var checkErr error
	hook := &ddl.TestDDLCallback{}
	hook.OnJobRunBeforeExported = func(job *model.Job) {
		if job.Type == model.ActionRenameIndex && job.State == model.JobStateNone {
			jobIDs := []int64{job.ID}
			hookCtx := mock.NewContext()
			hookCtx.Store = s.store
			err := hookCtx.NewTxn(context.Background())
			if err != nil {
				checkErr = errors.Trace(err)
				return
			}
			txn, err := hookCtx.Txn(true)
			if err != nil {
				checkErr = errors.Trace(err)
				return
			}
			errs, err := admin.CancelJobs(txn, jobIDs)
			if err != nil {
				checkErr = errors.Trace(err)
				return
			}
			if errs[0] != nil {
				checkErr = errors.Trace(errs[0])
				return
			}
			checkErr = txn.Commit(context.Background())
		}
	}
	originalHook := s.dom.DDL().GetHook()
	s.dom.DDL().(ddl.DDLForTest).SetHook(hook)
	rs, err := s.tk.Exec("alter table t rename index idx_c2 to idx_c3")
	if rs != nil {
		rs.Close()
	}
	c.Assert(checkErr, IsNil)
	c.Assert(err, NotNil)
	c.Assert(err.Error(), Equals, "[ddl:8214]Cancelled DDL job")
	s.dom.DDL().(ddl.DDLForTest).SetHook(originalHook)
	t := s.testGetTable(c, "t")
	for _, idx := range t.Indices() {
		c.Assert(strings.EqualFold(idx.Meta().Name.L, "idx_c3"), IsFalse)
	}
	s.mustExec(c, "alter table t rename index idx_c2 to idx_c3")
}

// TestCancelDropTable tests cancel ddl job which type is drop table.
func (s *testDBSuite2) TestCancelDropTableAndSchema(c *C) {
	s.tk = testkit.NewTestKit(c, s.store)
	testCases := []struct {
		needAddTableOrDB bool
		action           model.ActionType
		jobState         model.JobState
		JobSchemaState   model.SchemaState
		cancelSucc       bool
	}{
		// Check drop table.
		// model.JobStateNone means the jobs is canceled before the first run.
		{true, model.ActionDropTable, model.JobStateNone, model.StateNone, true},
		{false, model.ActionDropTable, model.JobStateRunning, model.StateWriteOnly, false},
		{true, model.ActionDropTable, model.JobStateRunning, model.StateDeleteOnly, false},

		// Check drop database.
		{true, model.ActionDropSchema, model.JobStateNone, model.StateNone, true},
		{false, model.ActionDropSchema, model.JobStateRunning, model.StateWriteOnly, false},
		{true, model.ActionDropSchema, model.JobStateRunning, model.StateDeleteOnly, false},
	}
	var checkErr error
	hook := &ddl.TestDDLCallback{}
	var jobID int64
	testCase := &testCases[0]
	s.mustExec(c, "create database if not exists test_drop_db")
	dbInfo := s.testGetDB(c, "test_drop_db")

	hook.OnJobRunBeforeExported = func(job *model.Job) {
		if job.Type == testCase.action && job.State == testCase.jobState && job.SchemaState == testCase.JobSchemaState && job.SchemaID == dbInfo.ID {
			jobIDs := []int64{job.ID}
			jobID = job.ID
			hookCtx := mock.NewContext()
			hookCtx.Store = s.store
			err := hookCtx.NewTxn(context.TODO())
			if err != nil {
				checkErr = errors.Trace(err)
				return
			}
			txn, err := hookCtx.Txn(true)
			if err != nil {
				checkErr = errors.Trace(err)
				return
			}
			errs, err := admin.CancelJobs(txn, jobIDs)
			if err != nil {
				checkErr = errors.Trace(err)
				return
			}
			if errs[0] != nil {
				checkErr = errors.Trace(errs[0])
				return
			}
			checkErr = txn.Commit(context.Background())
		}
	}
	originHook := s.dom.DDL().GetHook()
	defer s.dom.DDL().(ddl.DDLForTest).SetHook(originHook)
	s.dom.DDL().(ddl.DDLForTest).SetHook(hook)
	var err error
	sql := ""
	for i := range testCases {
		testCase = &testCases[i]
		if testCase.needAddTableOrDB {
			s.mustExec(c, "create database if not exists test_drop_db")
			s.mustExec(c, "use test_drop_db")
			s.mustExec(c, "create table if not exists t(c1 int, c2 int)")
		}

		dbInfo = s.testGetDB(c, "test_drop_db")

		if testCase.action == model.ActionDropTable {
			sql = "drop table t;"
		} else if testCase.action == model.ActionDropSchema {
			sql = "drop database test_drop_db;"
		}

		_, err = s.tk.Exec(sql)
		if testCase.cancelSucc {
			c.Assert(checkErr, IsNil)
			c.Assert(err, NotNil)
			c.Assert(err.Error(), Equals, "[ddl:8214]Cancelled DDL job")
			s.mustExec(c, "insert into t values (?, ?)", i, i)
		} else {
			c.Assert(err, IsNil)
			c.Assert(checkErr, NotNil)
			c.Assert(checkErr.Error(), Equals, admin.ErrCannotCancelDDLJob.GenWithStackByArgs(jobID).Error())
			_, err = s.tk.Exec("insert into t values (?, ?)", i, i)
			c.Assert(err, NotNil)
		}
	}
}

func (s *testDBSuite3) TestAddAnonymousIndex(c *C) {
	s.tk = testkit.NewTestKit(c, s.store)
	s.tk.MustExec("use " + s.schemaName)
	s.mustExec(c, "create table t_anonymous_index (c1 int, c2 int, C3 int)")
	s.mustExec(c, "alter table t_anonymous_index add index (c1, c2)")
	// for dropping empty index
	_, err := s.tk.Exec("alter table t_anonymous_index drop index")
	c.Assert(err, NotNil)
	// The index name is c1 when adding index (c1, c2).
	s.mustExec(c, "alter table t_anonymous_index drop index c1")
	t := s.testGetTable(c, "t_anonymous_index")
	c.Assert(t.Indices(), HasLen, 0)
	// for adding some indices that the first column name is c1
	s.mustExec(c, "alter table t_anonymous_index add index (c1)")
	_, err = s.tk.Exec("alter table t_anonymous_index add index c1 (c2)")
	c.Assert(err, NotNil)
	t = s.testGetTable(c, "t_anonymous_index")
	c.Assert(t.Indices(), HasLen, 1)
	idx := t.Indices()[0].Meta().Name.L
	c.Assert(idx, Equals, "c1")
	// The MySQL will be a warning.
	s.mustExec(c, "alter table t_anonymous_index add index c1_3 (c1)")
	s.mustExec(c, "alter table t_anonymous_index add index (c1, c2, C3)")
	// The MySQL will be a warning.
	s.mustExec(c, "alter table t_anonymous_index add index (c1)")
	t = s.testGetTable(c, "t_anonymous_index")
	c.Assert(t.Indices(), HasLen, 4)
	s.mustExec(c, "alter table t_anonymous_index drop index c1")
	s.mustExec(c, "alter table t_anonymous_index drop index c1_2")
	s.mustExec(c, "alter table t_anonymous_index drop index c1_3")
	s.mustExec(c, "alter table t_anonymous_index drop index c1_4")
	// for case insensitive
	s.mustExec(c, "alter table t_anonymous_index add index (C3)")
	s.mustExec(c, "alter table t_anonymous_index drop index c3")
	s.mustExec(c, "alter table t_anonymous_index add index c3 (C3)")
	s.mustExec(c, "alter table t_anonymous_index drop index C3")
	// for anonymous index with column name `primary`
	s.mustExec(c, "create table t_primary (`primary` int, key (`primary`))")
	t = s.testGetTable(c, "t_primary")
	c.Assert(t.Indices()[0].Meta().Name.String(), Equals, "primary_2")
	s.mustExec(c, "create table t_primary_2 (`primary` int, key primary_2 (`primary`), key (`primary`))")
	t = s.testGetTable(c, "t_primary_2")
	c.Assert(t.Indices()[0].Meta().Name.String(), Equals, "primary_2")
	c.Assert(t.Indices()[1].Meta().Name.String(), Equals, "primary_3")
	s.mustExec(c, "create table t_primary_3 (`primary_2` int, key(`primary_2`), `primary` int, key(`primary`));")
	t = s.testGetTable(c, "t_primary_3")
	c.Assert(t.Indices()[0].Meta().Name.String(), Equals, "primary_2")
	c.Assert(t.Indices()[1].Meta().Name.String(), Equals, "primary_3")
}

func (s *testDBSuite4) TestAlterLock(c *C) {
	s.tk = testkit.NewTestKit(c, s.store)
	s.tk.MustExec("use " + s.schemaName)
	s.mustExec(c, "create table t_index_lock (c1 int, c2 int, C3 int)")
	s.mustExec(c, "alter table t_index_lock add index (c1, c2), lock=none")
}

func (s *testDBSuite5) TestAddMultiColumnsIndex(c *C) {
	s.tk = testkit.NewTestKit(c, s.store)
	s.tk.MustExec("use " + s.schemaName)

	s.tk.MustExec("drop database if exists tidb;")
	s.tk.MustExec("create database tidb;")
	s.tk.MustExec("use tidb;")
	s.tk.MustExec("create table tidb.test (a int auto_increment primary key, b int);")
	s.tk.MustExec("insert tidb.test values (1, 1);")
	s.tk.MustExec("update tidb.test set b = b + 1 where a = 1;")
	s.tk.MustExec("insert into tidb.test values (2, 2);")
	// Test that the b value is nil.
	s.tk.MustExec("insert into tidb.test (a) values (3);")
	s.tk.MustExec("insert into tidb.test values (4, 4);")
	// Test that the b value is nil again.
	s.tk.MustExec("insert into tidb.test (a) values (5);")
	s.tk.MustExec("insert tidb.test values (6, 6);")
	s.tk.MustExec("alter table tidb.test add index idx1 (a, b);")
	s.tk.MustExec("admin check table test")
}
func (s *testDBSuite1) TestAddPrimaryKey1(c *C) {
	testAddIndex(c, s.store, s.lease, false,
		"create table test_add_index (c1 bigint, c2 bigint, c3 bigint, unique key(c1))", "primary")
}

func (s *testDBSuite2) TestAddPrimaryKey2(c *C) {
	testAddIndex(c, s.store, s.lease, true,
		`create table test_add_index (c1 bigint, c2 bigint, c3 bigint, key(c1))
			      partition by range (c3) (
			      partition p0 values less than (3440),
			      partition p1 values less than (61440),
			      partition p2 values less than (122880),
			      partition p3 values less than (204800),
			      partition p4 values less than maxvalue)`, "primary")
}

func (s *testDBSuite3) TestAddPrimaryKey3(c *C) {
	testAddIndex(c, s.store, s.lease, true,
		`create table test_add_index (c1 bigint, c2 bigint, c3 bigint, key(c1))
			      partition by hash (c3) partitions 4;`, "primary")
}

func (s *testDBSuite4) TestAddPrimaryKey4(c *C) {
	testAddIndex(c, s.store, s.lease, true,
		`create table test_add_index (c1 bigint, c2 bigint, c3 bigint, key(c1))
			      partition by range columns (c3) (
			      partition p0 values less than (3440),
			      partition p1 values less than (61440),
			      partition p2 values less than (122880),
			      partition p3 values less than (204800),
			      partition p4 values less than maxvalue)`, "primary")
}

func (s *testDBSuite1) TestAddIndex1(c *C) {
	testAddIndex(c, s.store, s.lease, false,
		"create table test_add_index (c1 bigint, c2 bigint, c3 bigint, primary key(c1))", "")
}

func (s *testDBSuite2) TestAddIndex2(c *C) {
	testAddIndex(c, s.store, s.lease, true,
		`create table test_add_index (c1 bigint, c2 bigint, c3 bigint, primary key(c1))
			      partition by range (c1) (
			      partition p0 values less than (3440),
			      partition p1 values less than (61440),
			      partition p2 values less than (122880),
			      partition p3 values less than (204800),
			      partition p4 values less than maxvalue)`, "")
}

func (s *testDBSuite3) TestAddIndex3(c *C) {
	testAddIndex(c, s.store, s.lease, true,
		`create table test_add_index (c1 bigint, c2 bigint, c3 bigint, primary key(c1))
			      partition by hash (c1) partitions 4;`, "")
}

func (s *testDBSuite4) TestAddIndex4(c *C) {
	testAddIndex(c, s.store, s.lease, true,
		`create table test_add_index (c1 bigint, c2 bigint, c3 bigint, primary key(c1))
			      partition by range columns (c1) (
			      partition p0 values less than (3440),
			      partition p1 values less than (61440),
			      partition p2 values less than (122880),
			      partition p3 values less than (204800),
			      partition p4 values less than maxvalue)`, "")
}

func testAddIndex(c *C, store kv.Storage, lease time.Duration, testPartition bool, createTableSQL, idxTp string) {
	tk := testkit.NewTestKit(c, store)
	tk.MustExec("use test_db")
	if testPartition {
		tk.MustExec("set @@session.tidb_enable_table_partition = '1';")
	}
	tk.MustExec("drop table if exists test_add_index")
	tk.MustExec(createTableSQL)

	done := make(chan error, 1)
	start := -10
	num := defaultBatchSize
	// first add some rows
	for i := start; i < num; i++ {
		sql := fmt.Sprintf("insert into test_add_index values (%d, %d, %d)", i, i, i)
		tk.MustExec(sql)
	}

	// Add some discrete rows.
	maxBatch := 20
	batchCnt := 100
	otherKeys := make([]int, 0, batchCnt*maxBatch)
	// Make sure there are no duplicate keys.
	base := defaultBatchSize * 20
	for i := 1; i < batchCnt; i++ {
		n := base + i*defaultBatchSize + i
		for j := 0; j < rand.Intn(maxBatch); j++ {
			n += j
			sql := fmt.Sprintf("insert into test_add_index values (%d, %d, %d)", n, n, n)
			tk.MustExec(sql)
			otherKeys = append(otherKeys, n)
		}
	}
	// Encounter the value of math.MaxInt64 in middle of
	v := math.MaxInt64 - defaultBatchSize/2
	sql := fmt.Sprintf("insert into test_add_index values (%d, %d, %d)", v, v, v)
	tk.MustExec(sql)
	otherKeys = append(otherKeys, v)

	addIdxSQL := fmt.Sprintf("alter table test_add_index add %s key c3_index(c3)", idxTp)
	testddlutil.SessionExecInGoroutine(c, store, addIdxSQL, done)

	deletedKeys := make(map[int]struct{})

	ticker := time.NewTicker(lease / 2)
	defer ticker.Stop()
LOOP:
	for {
		select {
		case err := <-done:
			if err == nil {
				break LOOP
			}
			c.Assert(err, IsNil, Commentf("err:%v", errors.ErrorStack(err)))
		case <-ticker.C:
			// When the server performance is particularly poor,
			// the adding index operation can not be completed.
			// So here is a limit to the number of rows inserted.
			if num > defaultBatchSize*10 {
				break
			}
			step := 5
			// delete some rows, and add some data
			for i := num; i < num+step; i++ {
				n := rand.Intn(num)
				deletedKeys[n] = struct{}{}
				sql := fmt.Sprintf("delete from test_add_index where c1 = %d", n)
				tk.MustExec(sql)
				sql = fmt.Sprintf("insert into test_add_index values (%d, %d, %d)", i, i, i)
				tk.MustExec(sql)
			}
			num += step
		}
	}

	// get exists keys
	keys := make([]int, 0, num)
	for i := start; i < num; i++ {
		if _, ok := deletedKeys[i]; ok {
			continue
		}
		keys = append(keys, i)
	}
	keys = append(keys, otherKeys...)

	// test index key
	expectedRows := make([][]interface{}, 0, len(keys))
	for _, key := range keys {
		expectedRows = append(expectedRows, []interface{}{key})
	}
	rows := tk.MustQuery(fmt.Sprintf("select c1 from test_add_index where c3 >= %d order by c1", start)).Rows()
	matchRows(c, rows, expectedRows)

	tk.MustExec("admin check table test_add_index")
	if testPartition {
		return
	}

	// TODO: Support explain in future.
	// rows := s.mustQuery(c, "explain select c1 from test_add_index where c3 >= 100")

	// ay := dumpRows(c, rows)
	// c.Assert(strings.Contains(fmt.Sprintf("%v", ay), "c3_index"), IsTrue)

	// get all row handles
	ctx := tk.Se.(sessionctx.Context)
	c.Assert(ctx.NewTxn(context.Background()), IsNil)
	t := testGetTableByName(c, ctx, "test_db", "test_add_index")
	handles := make(map[int64]struct{})
	startKey := t.RecordKey(math.MinInt64)
	err := t.IterRecords(ctx, startKey, t.Cols(),
		func(h int64, data []types.Datum, cols []*table.Column) (bool, error) {
			handles[h] = struct{}{}
			return true, nil
		})
	c.Assert(err, IsNil)

	// check in index
	var nidx table.Index
	idxName := "c3_index"
	if len(idxTp) != 0 {
		idxName = "primary"
	}
	for _, tidx := range t.Indices() {
		if tidx.Meta().Name.L == idxName {
			nidx = tidx
			break
		}
	}
	// Make sure there is index with name c3_index.
	c.Assert(nidx, NotNil)
	c.Assert(nidx.Meta().ID, Greater, int64(0))
	txn, err := ctx.Txn(true)
	c.Assert(err, IsNil)
	txn.Rollback()

	c.Assert(ctx.NewTxn(context.Background()), IsNil)

	it, err := nidx.SeekFirst(txn)
	c.Assert(err, IsNil)
	defer it.Close()

	for {
		_, h, err := it.Next()
		if terror.ErrorEqual(err, io.EOF) {
			break
		}

		c.Assert(err, IsNil)
		_, ok := handles[h]
		c.Assert(ok, IsTrue)
		delete(handles, h)
	}
	c.Assert(handles, HasLen, 0)
	tk.MustExec("drop table test_add_index")
}

// TestCancelAddTableAndDropTablePartition tests cancel ddl job which type is add/drop table partition.
func (s *testDBSuite1) TestCancelAddTableAndDropTablePartition(c *C) {
	s.tk = testkit.NewTestKit(c, s.store)
	s.mustExec(c, "create database if not exists test_partition_table")
	s.mustExec(c, "use test_partition_table")
	s.mustExec(c, "drop table if exists t_part")
	s.mustExec(c, `create table t_part (a int key)
		partition by range(a) (
		partition p0 values less than (10),
		partition p1 values less than (20)
	);`)
	defer s.mustExec(c, "drop table t_part;")
	for i := 0; i < 10; i++ {
		s.mustExec(c, "insert into t_part values (?)", i)
	}

	testCases := []struct {
		action         model.ActionType
		jobState       model.JobState
		JobSchemaState model.SchemaState
		cancelSucc     bool
	}{
		{model.ActionAddTablePartition, model.JobStateNone, model.StateNone, true},
		{model.ActionDropTablePartition, model.JobStateNone, model.StateNone, true},
		{model.ActionAddTablePartition, model.JobStateRunning, model.StatePublic, false},
		{model.ActionDropTablePartition, model.JobStateRunning, model.StatePublic, false},
	}
	var checkErr error
	hook := &ddl.TestDDLCallback{}
	testCase := &testCases[0]
	var jobID int64
	hook.OnJobRunBeforeExported = func(job *model.Job) {
		if job.Type == testCase.action && job.State == testCase.jobState && job.SchemaState == testCase.JobSchemaState {
			jobIDs := []int64{job.ID}
			jobID = job.ID
			hookCtx := mock.NewContext()
			hookCtx.Store = s.store
			err := hookCtx.NewTxn(context.Background())
			if err != nil {
				checkErr = errors.Trace(err)
				return
			}
			txn, err := hookCtx.Txn(true)
			if err != nil {
				checkErr = errors.Trace(err)
				return
			}
			errs, err := admin.CancelJobs(txn, jobIDs)
			if err != nil {
				checkErr = errors.Trace(err)
				return
			}
			if errs[0] != nil {
				checkErr = errors.Trace(errs[0])
				return
			}
			checkErr = txn.Commit(context.Background())
		}
		var err error
		sql := ""
		for i := range testCases {
			testCase = &testCases[i]
			if testCase.action == model.ActionAddTablePartition {
				sql = `alter table t_part add partition (
				partition p2 values less than (30)
				);`
			} else if testCase.action == model.ActionDropTablePartition {
				sql = "alter table t_part drop partition p1;"
			}
			_, err = s.tk.Exec(sql)
			if testCase.cancelSucc {
				c.Assert(checkErr, IsNil)
				c.Assert(err, NotNil)
				c.Assert(err.Error(), Equals, "[ddl:12]cancelled DDL job")
				s.mustExec(c, "insert into t_part values (?)", i)
			} else {
				c.Assert(err, IsNil)
				c.Assert(checkErr, NotNil)
				c.Assert(checkErr.Error(), Equals, admin.ErrCannotCancelDDLJob.GenWithStackByArgs(jobID).Error())
				_, err = s.tk.Exec("insert into t_part values (?)", i)
				c.Assert(err, NotNil)
			}
		}
	}
	originalHook := s.dom.DDL().GetHook()
	s.dom.DDL().(ddl.DDLForTest).SetHook(originalHook)
}

func (s *testDBSuite1) TestDropPrimaryKey(c *C) {
	idxName := "primary"
	createSQL := "create table test_drop_index (c1 int, c2 int, c3 int, unique key(c1), primary key(c3))"
	dropIdxSQL := "alter table test_drop_index drop primary key;"
	testDropIndex(c, s.store, s.lease, createSQL, dropIdxSQL, idxName)
}

func (s *testDBSuite2) TestDropIndex(c *C) {
	idxName := "c3_index"
	createSQL := "create table test_drop_index (c1 int, c2 int, c3 int, unique key(c1), key c3_index(c3))"
	dropIdxSQL := "alter table test_drop_index drop index c3_index;"
	testDropIndex(c, s.store, s.lease, createSQL, dropIdxSQL, idxName)
}

func testDropIndex(c *C, store kv.Storage, lease time.Duration, createSQL, dropIdxSQL, idxName string) {
	tk := testkit.NewTestKit(c, store)
	tk.MustExec("use test_db")
	tk.MustExec("drop table if exists test_drop_index")
	tk.MustExec(createSQL)
	done := make(chan error, 1)
	tk.MustExec("delete from test_drop_index")

	num := 100
	//  add some rows
	for i := 0; i < num; i++ {
		tk.MustExec("insert into test_drop_index values (?, ?, ?)", i, i, i)
	}
	ctx := tk.Se.(sessionctx.Context)
	t := testGetTableByName(c, ctx, "test_db", "test_drop_index")
	var c3idx table.Index
	for _, tidx := range t.Indices() {
		if tidx.Meta().Name.L == idxName {
			c3idx = tidx
			break
		}
	}
	c.Assert(c3idx, NotNil)

	testddlutil.SessionExecInGoroutine(c, store, dropIdxSQL, done)

	ticker := time.NewTicker(lease / 2)
	defer ticker.Stop()
LOOP:
	for {
		select {
		case err := <-done:
			if err == nil {
				break LOOP
			}
			c.Assert(err, IsNil, Commentf("err:%v", errors.ErrorStack(err)))
		case <-ticker.C:
			step := 5
			// delete some rows, and add some data
			for i := num; i < num+step; i++ {
				n := rand.Intn(num)
				tk.MustExec("update test_drop_index set c2 = 1 where c1 = ?", n)
				tk.MustExec("insert into test_drop_index values (?, ?, ?)", i, i, i)
			}
			num += step
		}
	}

	rows := tk.MustQuery("explain select c1 from test_drop_index where c3 >= 0")
	c.Assert(strings.Contains(fmt.Sprintf("%v", rows), idxName), IsFalse)

	// Check in index, it must be no index in KV.
	// Make sure there is no index with name c3_index.
	t = testGetTableByName(c, ctx, "test_db", "test_drop_index")
	var nidx table.Index
	for _, tidx := range t.Indices() {
		if tidx.Meta().Name.L == idxName {
			nidx = tidx
			break
		}
	}
	c.Assert(nidx, IsNil)

	idx := tables.NewIndex(t.Meta().ID, t.Meta(), c3idx.Meta())
	checkDelRangeDone(c, ctx, idx)
	tk.MustExec("drop table test_drop_index")
}

// TestCancelDropColumn tests cancel ddl job which type is drop column.
func (s *testDBSuite3) TestCancelDropColumn(c *C) {
	s.tk = testkit.NewTestKit(c, s.store)
	s.tk.MustExec("use " + s.schemaName)
	s.mustExec(c, "drop table if exists test_drop_column")
	s.mustExec(c, "create table test_drop_column(c1 int, c2 int)")
	defer s.mustExec(c, "drop table test_drop_column;")
	testCases := []struct {
		needAddColumn  bool
		jobState       model.JobState
		JobSchemaState model.SchemaState
		cancelSucc     bool
	}{
		{true, model.JobStateNone, model.StateNone, true},
		{false, model.JobStateRunning, model.StateWriteOnly, false},
		{true, model.JobStateRunning, model.StateDeleteOnly, false},
		{true, model.JobStateRunning, model.StateDeleteReorganization, false},
	}
	var checkErr error
	hook := &ddl.TestDDLCallback{}
	var jobID int64
	testCase := &testCases[0]
	hook.OnJobRunBeforeExported = func(job *model.Job) {
		if job.Type == model.ActionDropColumn && job.State == testCase.jobState && job.SchemaState == testCase.JobSchemaState {
			jobIDs := []int64{job.ID}
			jobID = job.ID
			hookCtx := mock.NewContext()
			hookCtx.Store = s.store
			err := hookCtx.NewTxn(context.TODO())
			if err != nil {
				checkErr = errors.Trace(err)
				return
			}
			txn, err := hookCtx.Txn(true)
			if err != nil {
				checkErr = errors.Trace(err)
				return
			}
			errs, err := admin.CancelJobs(txn, jobIDs)
			if err != nil {
				checkErr = errors.Trace(err)
				return
			}
			if errs[0] != nil {
				checkErr = errors.Trace(errs[0])
				return
			}
			checkErr = txn.Commit(context.Background())
		}
	}

	originalHook := s.dom.DDL().GetHook()
	s.dom.DDL().(ddl.DDLForTest).SetHook(hook)
	var err1 error
	for i := range testCases {
		testCase = &testCases[i]
		if testCase.needAddColumn {
			s.mustExec(c, "alter table test_drop_column add column c3 int")
		}
		_, err1 = s.tk.Exec("alter table test_drop_column drop column c3")
		var col1 *table.Column
		t := s.testGetTable(c, "test_drop_column")
		for _, col := range t.Cols() {
			if strings.EqualFold(col.Name.L, "c3") {
				col1 = col
				break
			}
		}
		if testCase.cancelSucc {
			c.Assert(checkErr, IsNil)
			c.Assert(col1, NotNil)
			c.Assert(col1.Name.L, Equals, "c3")
			c.Assert(err1.Error(), Equals, "[ddl:8214]Cancelled DDL job")
		} else {
			c.Assert(col1, IsNil)
			c.Assert(err1, IsNil)
			c.Assert(checkErr, NotNil)
			c.Assert(checkErr.Error(), Equals, admin.ErrCannotCancelDDLJob.GenWithStackByArgs(jobID).Error())
		}
	}
	s.dom.DDL().(ddl.DDLForTest).SetHook(originalHook)
	s.mustExec(c, "alter table test_drop_column add column c3 int")
	s.mustExec(c, "alter table test_drop_column drop column c3")
}

func checkDelRangeDone(c *C, ctx sessionctx.Context, idx table.Index) {
	startTime := time.Now()
	f := func() map[int64]struct{} {
		handles := make(map[int64]struct{})

		c.Assert(ctx.NewTxn(context.Background()), IsNil)
		txn, err := ctx.Txn(true)
		c.Assert(err, IsNil)
		defer txn.Rollback()

		txn, err = ctx.Txn(true)
		c.Assert(err, IsNil)
		it, err := idx.SeekFirst(txn)
		c.Assert(err, IsNil)
		defer it.Close()

		for {
			_, h, err := it.Next()
			if terror.ErrorEqual(err, io.EOF) {
				break
			}

			c.Assert(err, IsNil)
			handles[h] = struct{}{}
		}
		return handles
	}

	var handles map[int64]struct{}
	for i := 0; i < waitForCleanDataRound; i++ {
		handles = f()
		if len(handles) != 0 {
			time.Sleep(waitForCleanDataInterval)
		} else {
			break
		}
	}
	c.Assert(handles, HasLen, 0, Commentf("take time %v", time.Since(startTime)))
}

func (s *testDBSuite5) TestAlterPrimaryKey(c *C) {
	s.tk = testkit.NewTestKitWithInit(c, s.store)
	s.tk.MustExec("create table test_add_pk(a int, b int unsigned , c varchar(255) default 'abc', d int as (a+b), e int as (a+1) stored, index idx(b))")
	defer s.tk.MustExec("drop table test_add_pk")

	// for generated columns
	s.tk.MustGetErrCode("alter table test_add_pk add primary key(d);", mysql.ErrUnsupportedOnGeneratedColumn)
	// The primary key name is the same as the existing index name.
	s.tk.MustExec("alter table test_add_pk add primary key idx(e)")
	s.tk.MustExec("alter table test_add_pk drop primary key")

	// for describing table
	s.tk.MustExec("create table test_add_pk1(a int, index idx(a))")
	s.tk.MustQuery("desc test_add_pk1").Check(testutil.RowsWithSep(",", `a,int(11),YES,MUL,<nil>,`))
	s.tk.MustExec("alter table test_add_pk1 add primary key idx(a)")
	s.tk.MustQuery("desc test_add_pk1").Check(testutil.RowsWithSep(",", `a,int(11),NO,PRI,<nil>,`))
	s.tk.MustExec("alter table test_add_pk1 drop primary key")
	s.tk.MustQuery("desc test_add_pk1").Check(testutil.RowsWithSep(",", `a,int(11),NO,MUL,<nil>,`))
	s.tk.MustExec("create table test_add_pk2(a int, b int, index idx(a))")
	s.tk.MustExec("alter table test_add_pk2 add primary key idx(a, b)")
	s.tk.MustQuery("desc test_add_pk2").Check(testutil.RowsWithSep(",", ""+
		"a int(11) NO PRI <nil> ]\n"+
		"[b int(11) NO PRI <nil> "))
	s.tk.MustQuery("show create table test_add_pk2").Check(testutil.RowsWithSep("|", ""+
		"test_add_pk2 CREATE TABLE `test_add_pk2` (\n"+
		"  `a` int(11) NOT NULL,\n"+
		"  `b` int(11) NOT NULL,\n"+
		"  KEY `idx` (`a`),\n"+
		"  PRIMARY KEY (`a`,`b`)\n"+
		") ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin"))
	s.tk.MustExec("alter table test_add_pk2 drop primary key")
	s.tk.MustQuery("desc test_add_pk2").Check(testutil.RowsWithSep(",", ""+
		"a int(11) NO MUL <nil> ]\n"+
		"[b int(11) NO  <nil> "))

	// Check if the primary key exists before checking the table's pkIsHandle.
	s.tk.MustGetErrCode("alter table test_add_pk drop primary key", mysql.ErrCantDropFieldOrKey)

	// for the limit of name
	validName := strings.Repeat("a", mysql.MaxIndexIdentifierLen)
	invalidName := strings.Repeat("b", mysql.MaxIndexIdentifierLen+1)
	s.tk.MustGetErrCode("alter table test_add_pk add primary key "+invalidName+"(a)", mysql.ErrTooLongIdent)
	// for valid name
	s.tk.MustExec("alter table test_add_pk add primary key " + validName + "(a)")
	// for multiple primary key
	s.tk.MustGetErrCode("alter table test_add_pk add primary key (a)", mysql.ErrMultiplePriKey)
	s.tk.MustExec("alter table test_add_pk drop primary key")
	// for not existing primary key
	s.tk.MustGetErrCode("alter table test_add_pk drop primary key", mysql.ErrCantDropFieldOrKey)

	// for too many key parts specified
	s.tk.MustGetErrCode("alter table test_add_pk add primary key idx_test(f1,f2,f3,f4,f5,f6,f7,f8,f9,f10,f11,f12,f13,f14,f15,f16,f17);",
		mysql.ErrTooManyKeyParts)

	// for the limit of comment's length
	validComment := "'" + strings.Repeat("a", ddl.MaxCommentLength) + "'"
	invalidComment := "'" + strings.Repeat("b", ddl.MaxCommentLength+1) + "'"
	s.tk.MustGetErrCode("alter table test_add_pk add primary key(a) comment "+invalidComment, mysql.ErrTooLongIndexComment)
	// for empty sql_mode
	r := s.tk.MustQuery("select @@sql_mode")
	sqlMode := r.Rows()[0][0].(string)
	s.tk.MustExec("set @@sql_mode=''")
	s.tk.MustExec("alter table test_add_pk add primary key(a) comment " + invalidComment)
	c.Assert(s.tk.Se.GetSessionVars().StmtCtx.WarningCount(), Equals, uint16(1))
	s.tk.MustQuery("show warnings").Check(testutil.RowsWithSep("|", "Warning|1688|Comment for index 'PRIMARY' is too long (max = 1024)"))
	s.tk.MustExec("set @@sql_mode= '" + sqlMode + "'")
	s.tk.MustExec("alter table test_add_pk drop primary key")
	// for valid comment
	s.tk.MustExec("alter table test_add_pk add primary key(a, b, c) comment " + validComment)
	ctx := s.tk.Se.(sessionctx.Context)
	c.Assert(ctx.NewTxn(context.Background()), IsNil)
	t := testGetTableByName(c, ctx, "test", "test_add_pk")
	col1Flag := t.Cols()[0].Flag
	col2Flag := t.Cols()[1].Flag
	col3Flag := t.Cols()[2].Flag
	c.Assert(mysql.HasNotNullFlag(col1Flag) && !mysql.HasPreventNullInsertFlag(col1Flag), IsTrue)
	c.Assert(mysql.HasNotNullFlag(col2Flag) && !mysql.HasPreventNullInsertFlag(col2Flag) && mysql.HasUnsignedFlag(col2Flag), IsTrue)
	c.Assert(mysql.HasNotNullFlag(col3Flag) && !mysql.HasPreventNullInsertFlag(col3Flag) && !mysql.HasNoDefaultValueFlag(col3Flag), IsTrue)
	s.tk.MustExec("alter table test_add_pk drop primary key")

	// for null values in primary key
	s.tk.MustExec("drop table test_add_pk")
	s.tk.MustExec("create table test_add_pk(a int, b int unsigned , c varchar(255) default 'abc', index idx(b))")
	s.tk.MustExec("insert into test_add_pk set a = 0, b = 0, c = 0")
	s.tk.MustExec("insert into test_add_pk set a = 1")
	s.tk.MustGetErrCode("alter table test_add_pk add primary key (b)", mysql.ErrInvalidUseOfNull)
	s.tk.MustExec("insert into test_add_pk set a = 2, b = 2")
	s.tk.MustGetErrCode("alter table test_add_pk add primary key (a, b)", mysql.ErrInvalidUseOfNull)
	s.tk.MustExec("insert into test_add_pk set a = 3, c = 3")
	s.tk.MustGetErrCode("alter table test_add_pk add primary key (c, b, a)", mysql.ErrInvalidUseOfNull)
}

func (s *testDBSuite4) TestAddIndexWithDupCols(c *C) {
	s.tk = testkit.NewTestKit(c, s.store)
	s.tk.MustExec("use " + s.schemaName)
	err1 := infoschema.ErrColumnExists.GenWithStackByArgs("b")
	err2 := infoschema.ErrColumnExists.GenWithStackByArgs("B")

	s.tk.MustExec("create table test_add_index_with_dup (a int, b int)")
	_, err := s.tk.Exec("create index c on test_add_index_with_dup(b, a, b)")
	c.Check(errors.Cause(err1).(*terror.Error).Equal(err), Equals, true)

	_, err = s.tk.Exec("create index c on test_add_index_with_dup(b, a, B)")
	c.Check(errors.Cause(err2).(*terror.Error).Equal(err), Equals, true)

	_, err = s.tk.Exec("alter table test_add_index_with_dup add index c (b, a, b)")
	c.Check(errors.Cause(err1).(*terror.Error).Equal(err), Equals, true)

	_, err = s.tk.Exec("alter table test_add_index_with_dup add index c (b, a, B)")
	c.Check(errors.Cause(err2).(*terror.Error).Equal(err), Equals, true)

	s.tk.MustExec("drop table test_add_index_with_dup")
}

func (s *testDBSuite) showColumns(c *C, tableName string) [][]interface{} {
	return s.mustQuery(c, fmt.Sprintf("show columns from %s", tableName))
}

func (s *testDBSuite5) TestCreateIndexType(c *C) {
	s.tk = testkit.NewTestKit(c, s.store)
	s.tk.MustExec("use " + s.schemaName)
	sql := `CREATE TABLE test_index (
		price int(5) DEFAULT '0' NOT NULL,
		area varchar(40) DEFAULT '' NOT NULL,
		type varchar(40) DEFAULT '' NOT NULL,
		transityes set('a','b'),
		shopsyes enum('Y','N') DEFAULT 'Y' NOT NULL,
		schoolsyes enum('Y','N') DEFAULT 'Y' NOT NULL,
		petsyes enum('Y','N') DEFAULT 'Y' NOT NULL,
		KEY price (price,area,type,transityes,shopsyes,schoolsyes,petsyes));`
	s.tk.MustExec(sql)
}

func (s *testDBSuite1) TestColumn(c *C) {
	s.tk = testkit.NewTestKit(c, s.store)
	s.tk.MustExec("use " + s.schemaName)
	s.tk.MustExec("create table t2 (c1 int, c2 int, c3 int)")
	s.tk.MustExec("set @@tidb_disable_txn_auto_retry = 0")
	s.testAddColumn(c)
	s.testDropColumn(c)
	s.tk.MustExec("drop table t2")
}

func (s *testDBSuite1) TestAddColumnTooMany(c *C) {
	s.tk = testkit.NewTestKit(c, s.store)
	s.tk.MustExec("use test")
	count := int(atomic.LoadUint32(&ddl.TableColumnCountLimit) - 1)
	var cols []string
	for i := 0; i < count; i++ {
		cols = append(cols, fmt.Sprintf("a%d int", i))
	}
	createSQL := fmt.Sprintf("create table t_column_too_many (%s)", strings.Join(cols, ","))
	s.tk.MustExec(createSQL)
	s.tk.MustExec("alter table t_column_too_many add column a_512 int")
	alterSQL := "alter table t_column_too_many add column a_513 int"
	s.tk.MustGetErrCode(alterSQL, mysql.ErrTooManyFields)
}

func sessionExec(c *C, s kv.Storage, sql string) {
	se, err := session.CreateSession4Test(s)
	c.Assert(err, IsNil)
	_, err = se.Execute(context.Background(), "use test_db")
	c.Assert(err, IsNil)
	rs, err := se.Execute(context.Background(), sql)
	c.Assert(err, IsNil, Commentf("err:%v", errors.ErrorStack(err)))
	c.Assert(rs, IsNil)
	se.Close()
}

func (s *testDBSuite) testAddColumn(c *C) {
	done := make(chan error, 1)

	num := defaultBatchSize + 10
	// add some rows
	batchInsert(s.tk, "t2", 0, num)

	testddlutil.SessionExecInGoroutine(c, s.store, "alter table t2 add column c4 int default -1", done)

	ticker := time.NewTicker(s.lease / 2)
	defer ticker.Stop()
	step := 10
LOOP:
	for {
		select {
		case err := <-done:
			if err == nil {
				break LOOP
			}
			c.Assert(err, IsNil, Commentf("err:%v", errors.ErrorStack(err)))
		case <-ticker.C:
			// delete some rows, and add some data
			for i := num; i < num+step; i++ {
				n := rand.Intn(num)
				s.tk.MustExec("begin")
				s.tk.MustExec("delete from t2 where c1 = ?", n)
				s.tk.MustExec("commit")

				// Make sure that statement of insert and show use the same infoSchema.
				s.tk.MustExec("begin")
				_, err := s.tk.Exec("insert into t2 values (?, ?, ?)", i, i, i)
				if err != nil {
					// if err is failed, the column number must be 4 now.
					values := s.showColumns(c, "t2")
					c.Assert(values, HasLen, 4, Commentf("err:%v", errors.ErrorStack(err)))
				}
				s.tk.MustExec("commit")
			}
			num += step
		}
	}

	// add data, here c4 must exist
	for i := num; i < num+step; i++ {
		s.tk.MustExec("insert into t2 values (?, ?, ?, ?)", i, i, i, i)
	}

	rows := s.mustQuery(c, "select count(c4) from t2")
	c.Assert(rows, HasLen, 1)
	c.Assert(rows[0], HasLen, 1)
	count, err := strconv.ParseInt(rows[0][0].(string), 10, 64)
	c.Assert(err, IsNil)
	c.Assert(count, Greater, int64(0))

	rows = s.mustQuery(c, "select count(c4) from t2 where c4 = -1")
	matchRows(c, rows, [][]interface{}{{count - int64(step)}})

	for i := num; i < num+step; i++ {
		rows = s.mustQuery(c, "select c4 from t2 where c4 = ?", i)
		matchRows(c, rows, [][]interface{}{{i}})
	}

	ctx := s.s.(sessionctx.Context)
	t := s.testGetTable(c, "t2")
	i := 0
	j := 0
	ctx.NewTxn(context.Background())
	defer func() {
		if txn, err1 := ctx.Txn(true); err1 == nil {
			txn.Rollback()
		}
	}()
	err = t.IterRecords(ctx, t.FirstKey(), t.Cols(),
		func(h int64, data []types.Datum, cols []*table.Column) (bool, error) {
			i++
			// c4 must be -1 or > 0
			v, err1 := data[3].ToInt64(ctx.GetSessionVars().StmtCtx)
			c.Assert(err1, IsNil)
			if v == -1 {
				j++
			} else {
				c.Assert(v, Greater, int64(0))
			}
			return true, nil
		})
	c.Assert(err, IsNil)
	c.Assert(i, Equals, int(count))
	c.Assert(i, LessEqual, num+step)
	c.Assert(j, Equals, int(count)-step)

	// for modifying columns after adding columns
	s.tk.MustExec("alter table t2 modify c4 int default 11")
	for i := num + step; i < num+step+10; i++ {
		s.mustExec(c, "insert into t2 values (?, ?, ?, ?)", i, i, i, i)
	}
	rows = s.mustQuery(c, "select count(c4) from t2 where c4 = -1")
	matchRows(c, rows, [][]interface{}{{count - int64(step)}})

	// add timestamp type column
	s.mustExec(c, "create table test_on_update_c (c1 int, c2 timestamp);")
	s.mustExec(c, "alter table test_on_update_c add column c3 timestamp null default '2017-02-11' on update current_timestamp;")
	is := domain.GetDomain(ctx).InfoSchema()
	tbl, err := is.TableByName(model.NewCIStr("test_db"), model.NewCIStr("test_on_update_c"))
	c.Assert(err, IsNil)
	tblInfo := tbl.Meta()
	colC := tblInfo.Columns[2]
	c.Assert(colC.Tp, Equals, mysql.TypeTimestamp)
	hasNotNull := mysql.HasNotNullFlag(colC.Flag)
	c.Assert(hasNotNull, IsFalse)
	// add datetime type column
	s.mustExec(c, "create table test_on_update_d (c1 int, c2 datetime);")
	s.mustExec(c, "alter table test_on_update_d add column c3 datetime on update current_timestamp;")
	is = domain.GetDomain(ctx).InfoSchema()
	tbl, err = is.TableByName(model.NewCIStr("test_db"), model.NewCIStr("test_on_update_d"))
	c.Assert(err, IsNil)
	tblInfo = tbl.Meta()
	colC = tblInfo.Columns[2]
	c.Assert(colC.Tp, Equals, mysql.TypeDatetime)
	hasNotNull = mysql.HasNotNullFlag(colC.Flag)
	c.Assert(hasNotNull, IsFalse)

	// test add unsupported constraint
	s.mustExec(c, "create table t_add_unsupported_constraint (a int);")
	_, err = s.tk.Exec("ALTER TABLE t_add_unsupported_constraint ADD id int AUTO_INCREMENT;")
	c.Assert(err.Error(), Equals, "[ddl:8200]unsupported add column 'id' constraint AUTO_INCREMENT when altering 'test_db.t_add_unsupported_constraint'")
	_, err = s.tk.Exec("ALTER TABLE t_add_unsupported_constraint ADD id int KEY;")
	c.Assert(err.Error(), Equals, "[ddl:8200]unsupported add column 'id' constraint PRIMARY KEY when altering 'test_db.t_add_unsupported_constraint'")
	_, err = s.tk.Exec("ALTER TABLE t_add_unsupported_constraint ADD id int UNIQUE;")
	c.Assert(err.Error(), Equals, "[ddl:8200]unsupported add column 'id' constraint UNIQUE KEY when altering 'test_db.t_add_unsupported_constraint'")
}

func (s *testDBSuite) testDropColumn(c *C) {
	done := make(chan error, 1)
	s.mustExec(c, "delete from t2")

	num := 100
	// add some rows
	for i := 0; i < num; i++ {
		s.mustExec(c, "insert into t2 values (?, ?, ?, ?)", i, i, i, i)
	}

	// get c4 column id
	testddlutil.SessionExecInGoroutine(c, s.store, "alter table t2 drop column c4", done)

	ticker := time.NewTicker(s.lease / 2)
	defer ticker.Stop()
	step := 10
LOOP:
	for {
		select {
		case err := <-done:
			if err == nil {
				break LOOP
			}
			c.Assert(err, IsNil, Commentf("err:%v", errors.ErrorStack(err)))
		case <-ticker.C:
			// delete some rows, and add some data
			for i := num; i < num+step; i++ {
				// Make sure that statement of insert and show use the same infoSchema.
				s.tk.MustExec("begin")
				_, err := s.tk.Exec("insert into t2 values (?, ?, ?)", i, i, i)
				if err != nil {
					// If executing is failed, the column number must be 4 now.
					values := s.showColumns(c, "t2")
					c.Assert(values, HasLen, 4, Commentf("err:%v", errors.ErrorStack(err)))
				}
				s.tk.MustExec("commit")
			}
			num += step
		}
	}

	// add data, here c4 must not exist
	for i := num; i < num+step; i++ {
		s.mustExec(c, "insert into t2 values (?, ?, ?)", i, i, i)
	}

	rows := s.mustQuery(c, "select count(*) from t2")
	c.Assert(rows, HasLen, 1)
	c.Assert(rows[0], HasLen, 1)
	count, err := strconv.ParseInt(rows[0][0].(string), 10, 64)
	c.Assert(err, IsNil)
	c.Assert(count, Greater, int64(0))
}

// TestDropColumn is for inserting value with a to-be-dropped column when do drop column.
// Column info from schema in build-insert-plan should be public only,
// otherwise they will not be consist with Table.Col(), then the server will panic.
func (s *testDBSuite2) TestDropColumn(c *C) {
	s.tk = testkit.NewTestKit(c, s.store)
	s.tk.MustExec("create database drop_col_db")
	s.tk.MustExec("use drop_col_db")
	num := 25
	multiDDL := make([]string, 0, num)
	sql := "create table t2 (c1 int, c2 int, c3 int, "
	for i := 4; i < 4+num; i++ {
		multiDDL = append(multiDDL, fmt.Sprintf("alter table t2 drop column c%d", i))

		if i != 3+num {
			sql += fmt.Sprintf("c%d int, ", i)
		} else {
			sql += fmt.Sprintf("c%d int)", i)
		}
	}
	s.tk.MustExec(sql)
	dmlDone := make(chan error, num)
	ddlDone := make(chan error, num)

	testddlutil.ExecMultiSQLInGoroutine(c, s.store, "drop_col_db", multiDDL, ddlDone)
	for i := 0; i < num; i++ {
		testddlutil.ExecMultiSQLInGoroutine(c, s.store, "drop_col_db", []string{"insert into t2 set c1 = 1, c2 = 1, c3 = 1, c4 = 1"}, dmlDone)
	}
	for i := 0; i < num; i++ {
		select {
		case err := <-ddlDone:
			c.Assert(err, IsNil, Commentf("err:%v", errors.ErrorStack(err)))
		}
	}

	// Test for drop partition table column.
	s.tk.MustExec("drop table if exists t1")
	s.tk.MustExec("create table t1 (a int,b int) partition by hash(a) partitions 4;")
	_, err := s.tk.Exec("alter table t1 drop column a")
	c.Assert(err, NotNil)
	c.Assert(err.Error(), Equals, "[expression:1054]Unknown column 'a' in 'expression'")

	s.tk.MustExec("drop database drop_col_db")
}

func (s *testDBSuite4) TestChangeColumn(c *C) {
	s.tk = testkit.NewTestKit(c, s.store)
	s.tk.MustExec("use " + s.schemaName)

	s.mustExec(c, "create table t3 (a int default '0', b varchar(10), d int not null default '0')")
	s.mustExec(c, "insert into t3 set b = 'a'")
	s.tk.MustQuery("select a from t3").Check(testkit.Rows("0"))
	s.mustExec(c, "alter table t3 change a aa bigint")
	s.mustExec(c, "insert into t3 set b = 'b'")
	s.tk.MustQuery("select aa from t3").Check(testkit.Rows("0", "<nil>"))
	// for no default flag
	s.mustExec(c, "alter table t3 change d dd bigint not null")
	ctx := s.tk.Se.(sessionctx.Context)
	is := domain.GetDomain(ctx).InfoSchema()
	tbl, err := is.TableByName(model.NewCIStr("test_db"), model.NewCIStr("t3"))
	c.Assert(err, IsNil)
	tblInfo := tbl.Meta()
	colD := tblInfo.Columns[2]
	hasNoDefault := mysql.HasNoDefaultValueFlag(colD.Flag)
	c.Assert(hasNoDefault, IsTrue)
	// for the following definitions: 'not null', 'null', 'default value' and 'comment'
	s.mustExec(c, "alter table t3 change b b varchar(20) null default 'c' comment 'my comment'")
	is = domain.GetDomain(ctx).InfoSchema()
	tbl, err = is.TableByName(model.NewCIStr("test_db"), model.NewCIStr("t3"))
	c.Assert(err, IsNil)
	tblInfo = tbl.Meta()
	colB := tblInfo.Columns[1]
	c.Assert(colB.Comment, Equals, "my comment")
	hasNotNull := mysql.HasNotNullFlag(colB.Flag)
	c.Assert(hasNotNull, IsFalse)
	s.mustExec(c, "insert into t3 set aa = 3, dd = 5")
	s.tk.MustQuery("select b from t3").Check(testkit.Rows("a", "b", "c"))
	// for timestamp
	s.mustExec(c, "alter table t3 add column c timestamp not null")
	s.mustExec(c, "alter table t3 change c c timestamp null default '2017-02-11' comment 'col c comment' on update current_timestamp")
	is = domain.GetDomain(ctx).InfoSchema()
	tbl, err = is.TableByName(model.NewCIStr("test_db"), model.NewCIStr("t3"))
	c.Assert(err, IsNil)
	tblInfo = tbl.Meta()
	colC := tblInfo.Columns[3]
	c.Assert(colC.Comment, Equals, "col c comment")
	hasNotNull = mysql.HasNotNullFlag(colC.Flag)
	c.Assert(hasNotNull, IsFalse)
	// for enum
	s.mustExec(c, "alter table t3 add column en enum('a', 'b', 'c') not null default 'a'")

	// for failing tests
	sql := "alter table t3 change aa a bigint default ''"
	s.tk.MustGetErrCode(sql, mysql.ErrInvalidDefault)
	sql = "alter table t3 change a testx.t3.aa bigint"
	s.tk.MustGetErrCode(sql, mysql.ErrWrongDBName)
	sql = "alter table t3 change t.a aa bigint"
	s.tk.MustGetErrCode(sql, mysql.ErrWrongTableName)
	s.mustExec(c, "create table t4 (c1 int, c2 int, c3 int default 1, index (c1));")
	s.tk.MustExec("insert into t4(c2) values (null);")
	sql = "alter table t4 change c1 a1 int not null;"
	s.tk.MustGetErrCode(sql, mysql.ErrInvalidUseOfNull)
	sql = "alter table t4 change c2 a bigint not null;"
	s.tk.MustGetErrCode(sql, mysql.WarnDataTruncated)
	sql = "alter table t3 modify en enum('a', 'z', 'b', 'c') not null default 'a'"
	s.tk.MustGetErrCode(sql, mysql.ErrUnsupportedDDLOperation)
	// Rename to an existing column.
	s.mustExec(c, "alter table t3 add column a bigint")
	sql = "alter table t3 change aa a bigint"
	s.tk.MustGetErrCode(sql, mysql.ErrDupFieldName)

	s.tk.MustExec("drop table t3")
}

func (s *testDBSuite) mustExec(c *C, query string, args ...interface{}) {
	s.tk.MustExec(query, args...)
}

func (s *testDBSuite) mustQuery(c *C, query string, args ...interface{}) [][]interface{} {
	r := s.tk.MustQuery(query, args...)
	return r.Rows()
}

func matchRows(c *C, rows [][]interface{}, expected [][]interface{}) {
	c.Assert(len(rows), Equals, len(expected), Commentf("got %v, expected %v", rows, expected))
	for i := range rows {
		match(c, rows[i], expected[i]...)
	}
}

func match(c *C, row []interface{}, expected ...interface{}) {
	c.Assert(len(row), Equals, len(expected))
	for i := range row {
		got := fmt.Sprintf("%v", row[i])
		need := fmt.Sprintf("%v", expected[i])
		c.Assert(got, Equals, need)
	}
}

// TestCreateTableWithLike2 tests create table with like when refer table have non-public column/index.
func (s *testDBSuite4) TestCreateTableWithLike2(c *C) {
	s.tk = testkit.NewTestKit(c, s.store)
	s.tk.MustExec("use test_db")
	s.tk.MustExec("drop table if exists t1,t2;")
	defer s.tk.MustExec("drop table if exists t1,t2;")
	s.tk.MustExec("create table t1 (a int, b int, c int, index idx1(c));")

	tbl1 := testGetTableByName(c, s.s, "test_db", "t1")
	doneCh := make(chan error, 2)
	hook := &ddl.TestDDLCallback{}
	var onceChecker sync.Map
	hook.OnJobRunBeforeExported = func(job *model.Job) {
		if job.Type != model.ActionAddColumn && job.Type != model.ActionDropColumn && job.Type != model.ActionAddIndex && job.Type != model.ActionDropIndex {
			return
		}
		if job.TableID != tbl1.Meta().ID {
			return
		}

		if job.SchemaState == model.StateDeleteOnly {
			if _, ok := onceChecker.Load(job.ID); ok {
				return
			}

			onceChecker.Store(job.ID, true)
			go backgroundExec(s.store, "create table t2 like t1", doneCh)
		}
	}
	originalHook := s.dom.DDL().GetHook()
	defer s.dom.DDL().(ddl.DDLForTest).SetHook(originalHook)
	s.dom.DDL().(ddl.DDLForTest).SetHook(hook)

	// create table when refer table add column
	s.tk.MustExec("alter table t1 add column d int")
	checkTbl2 := func() {
		err := <-doneCh
		c.Assert(err, IsNil)
		s.tk.MustExec("alter table t2 add column e int")
		t2Info := testGetTableByName(c, s.s, "test_db", "t2")
		c.Assert(len(t2Info.Meta().Columns), Equals, len(t2Info.Cols()))
	}
	checkTbl2()

	// create table when refer table drop column
	s.tk.MustExec("drop table t2;")
	s.tk.MustExec("alter table t1 drop column b;")
	checkTbl2()

	// create table when refer table add index
	s.tk.MustExec("drop table t2;")
	s.tk.MustExec("alter table t1 add index idx2(a);")
	checkTbl2 = func() {
		err := <-doneCh
		c.Assert(err, IsNil)
		s.tk.MustExec("alter table t2 add column e int")
		tbl2 := testGetTableByName(c, s.s, "test_db", "t2")
		c.Assert(len(tbl2.Meta().Columns), Equals, len(tbl2.Cols()))

		for i := 0; i < len(tbl2.Meta().Indices); i++ {
			c.Assert(tbl2.Meta().Indices[i].State, Equals, model.StatePublic)
		}
	}
	checkTbl2()

	// create table when refer table drop index.
	s.tk.MustExec("drop table t2;")
	s.tk.MustExec("alter table t1 drop index idx2;")
	checkTbl2()

}

func (s *testDBSuite1) TestCreateTable(c *C) {
	s.tk.MustExec("use test")
	s.tk.MustExec("CREATE TABLE `t` (`a` double DEFAULT 1.0 DEFAULT now() DEFAULT 2.0 );")
	s.tk.MustExec("CREATE TABLE IF NOT EXISTS `t` (`a` double DEFAULT 1.0 DEFAULT now() DEFAULT 2.0 );")
	ctx := s.tk.Se.(sessionctx.Context)
	is := domain.GetDomain(ctx).InfoSchema()
	tbl, err := is.TableByName(model.NewCIStr("test"), model.NewCIStr("t"))
	c.Assert(err, IsNil)
	cols := tbl.Cols()

	c.Assert(len(cols), Equals, 1)
	col := cols[0]
	c.Assert(col.Name.L, Equals, "a")
	d, ok := col.DefaultValue.(string)
	c.Assert(ok, IsTrue)
	c.Assert(d, Equals, "2.0")

	s.tk.MustExec("drop table t")

	s.tk.MustGetErrCode("CREATE TABLE `t` (`a` int) DEFAULT CHARSET=abcdefg", mysql.ErrUnknownCharacterSet)

	s.tk.MustExec("CREATE TABLE `collateTest` (`a` int, `b` varchar(10)) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_slovak_ci")
	expects := "CREATE TABLE `collateTest` (\n  `a` int(11) DEFAULT NULL,\n  `b` varchar(10) COLLATE utf8_slovak_ci DEFAULT NULL\n) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_slovak_ci"
	s.tk.MustQuery("show create table collateTest").Check(testkit.Rows(expects))

	s.tk.MustGetErrCode("CREATE TABLE `collateTest2` (`a` int) CHARSET utf8 COLLATE utf8mb4_unicode_ci", mysql.ErrCollationCharsetMismatch)
	s.tk.MustGetErrCode("CREATE TABLE `collateTest3` (`a` int) COLLATE utf8mb4_unicode_ci CHARSET utf8", mysql.ErrConflictingDeclarations)

	s.tk.MustExec("CREATE TABLE `collateTest4` (`a` int) COLLATE utf8_uniCOde_ci")
	expects = "CREATE TABLE `collateTest4` (\n  `a` int(11) DEFAULT NULL\n) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci"
	s.tk.MustQuery("show create table collateTest4").Check(testkit.Rows(expects))

	s.tk.MustExec("create database test2 default charset utf8 collate utf8_general_ci")
	s.tk.MustExec("use test2")
	s.tk.MustExec("create table dbCollateTest (a varchar(10))")
	expects = "CREATE TABLE `dbCollateTest` (\n  `a` varchar(10) COLLATE utf8_general_ci DEFAULT NULL\n) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_general_ci"
	s.tk.MustQuery("show create table dbCollateTest").Check(testkit.Rows(expects))

	// test for enum column
	s.tk.MustExec("use test")
	failSQL := "create table t_enum (a enum('e','e'));"
	s.tk.MustGetErrCode(failSQL, mysql.ErrDuplicatedValueInType)
	failSQL = "create table t_enum (a enum('e','E'));"
	s.tk.MustGetErrCode(failSQL, mysql.ErrDuplicatedValueInType)
	failSQL = "create table t_enum (a enum('abc','Abc'));"
	s.tk.MustGetErrCode(failSQL, mysql.ErrDuplicatedValueInType)
	// test for set column
	failSQL = "create table t_enum (a set('e','e'));"
	s.tk.MustGetErrCode(failSQL, mysql.ErrDuplicatedValueInType)
	failSQL = "create table t_enum (a set('e','E'));"
	s.tk.MustGetErrCode(failSQL, mysql.ErrDuplicatedValueInType)
	failSQL = "create table t_enum (a set('abc','Abc'));"
	s.tk.MustGetErrCode(failSQL, mysql.ErrDuplicatedValueInType)
	_, err = s.tk.Exec("create table t_enum (a enum('B','b'));")
	c.Assert(err.Error(), Equals, "[types:1291]Column 'a' has duplicated value 'B' in ENUM")
}

func (s *testDBSuite2) TestCreateTableWithSetCol(c *C) {
	s.tk = testkit.NewTestKitWithInit(c, s.store)
	s.tk.MustExec("create table t_set (a int, b set('e') default '');")
	s.tk.MustQuery("show create table t_set").Check(testkit.Rows("t_set CREATE TABLE `t_set` (\n" +
		"  `a` int(11) DEFAULT NULL,\n" +
		"  `b` set('e') DEFAULT ''\n" +
		") ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin"))
	s.tk.MustExec("drop table t_set")
	s.tk.MustExec("create table t_set (a set('a', 'b', 'c', 'd') default 'a,C,c');")
	s.tk.MustQuery("show create table t_set").Check(testkit.Rows("t_set CREATE TABLE `t_set` (\n" +
		"  `a` set('a','b','c','d') DEFAULT 'a,c'\n" +
		") ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin"))

	// It's for failure cases.
	// The type of default value is string.
	s.tk.MustExec("drop table t_set")
	failedSQL := "create table t_set (a set('1', '4', '10') default '3');"
	s.tk.MustGetErrCode(failedSQL, mysql.ErrInvalidDefault)
	failedSQL = "create table t_set (a set('1', '4', '10') default '1,4,11');"
	s.tk.MustGetErrCode(failedSQL, mysql.ErrInvalidDefault)
	failedSQL = "create table t_set (a set('1', '4', '10') default '1 ,4');"
	s.tk.MustGetErrCode(failedSQL, mysql.ErrInvalidDefault)
	// The type of default value is int.
	failedSQL = "create table t_set (a set('1', '4', '10') default 0);"
	s.tk.MustGetErrCode(failedSQL, mysql.ErrInvalidDefault)
	failedSQL = "create table t_set (a set('1', '4', '10') default 8);"
	s.tk.MustGetErrCode(failedSQL, mysql.ErrInvalidDefault)

	// The type of default value is int.
	// It's for successful cases
	s.tk.MustExec("create table t_set (a set('1', '4', '10', '21') default 1);")
	s.tk.MustQuery("show create table t_set").Check(testkit.Rows("t_set CREATE TABLE `t_set` (\n" +
		"  `a` set('1','4','10','21') DEFAULT '1'\n" +
		") ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin"))
	s.tk.MustExec("drop table t_set")
	s.tk.MustExec("create table t_set (a set('1', '4', '10', '21') default 2);")
	s.tk.MustQuery("show create table t_set").Check(testkit.Rows("t_set CREATE TABLE `t_set` (\n" +
		"  `a` set('1','4','10','21') DEFAULT '4'\n" +
		") ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin"))
	s.tk.MustExec("drop table t_set")
	s.tk.MustExec("create table t_set (a set('1', '4', '10', '21') default 3);")
	s.tk.MustQuery("show create table t_set").Check(testkit.Rows("t_set CREATE TABLE `t_set` (\n" +
		"  `a` set('1','4','10','21') DEFAULT '1,4'\n" +
		") ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin"))
	s.tk.MustExec("drop table t_set")
	s.tk.MustExec("create table t_set (a set('1', '4', '10', '21') default 15);")
	s.tk.MustQuery("show create table t_set").Check(testkit.Rows("t_set CREATE TABLE `t_set` (\n" +
		"  `a` set('1','4','10','21') DEFAULT '1,4,10,21'\n" +
		") ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin"))
	s.tk.MustExec("insert into t_set value()")
	s.tk.MustQuery("select * from t_set").Check(testkit.Rows("1,4,10,21"))
}

func (s *testDBSuite2) TestTableForeignKey(c *C) {
	s.tk = testkit.NewTestKit(c, s.store)
	s.tk.MustExec("use test")
	s.tk.MustExec("create table t1 (a int, b int);")
	// test create table with foreign key.
	failSQL := "create table t2 (c int, foreign key (a) references t1(a));"
	s.tk.MustGetErrCode(failSQL, mysql.ErrKeyColumnDoesNotExits)
	// test add foreign key.
	s.tk.MustExec("create table t3 (a int, b int);")
	failSQL = "alter table t1 add foreign key (c) REFERENCES t3(a);"
	s.tk.MustGetErrCode(failSQL, mysql.ErrKeyColumnDoesNotExits)
	// test oreign key not match error
	failSQL = "alter table t1 add foreign key (a) REFERENCES t3(a, b);"
	s.tk.MustGetErrCode(failSQL, mysql.ErrWrongFkDef)
	s.tk.MustExec("drop table if exists t1,t2,t3;")
}

func (s *testDBSuite3) TestFKOnGeneratedColumns(c *C) {
	s.tk = testkit.NewTestKit(c, s.store)
	s.tk.MustExec("use test")
	// test add foreign key to generated column

	// foreign key constraint cannot be defined on a virtual generated column.
	s.tk.MustExec("create table t1 (a int primary key);")
	s.tk.MustGetErrCode("create table t2 (a int, b int as (a+1) virtual, foreign key (b) references t1(a));", mysql.ErrCannotAddForeign)
	s.tk.MustExec("create table t2 (a int, b int generated always as (a+1) virtual);")
	s.tk.MustGetErrCode("alter table t2 add foreign key (b) references t1(a);", mysql.ErrCannotAddForeign)
	s.tk.MustExec("drop table t1, t2;")

	// foreign key constraint can be defined on a stored generated column.
	s.tk.MustExec("create table t2 (a int primary key);")
	s.tk.MustExec("create table t1 (a int, b int as (a+1) stored, foreign key (b) references t2(a));")
	s.tk.MustExec("create table t3 (a int, b int generated always as (a+1) stored);")
	s.tk.MustExec("alter table t3 add foreign key (b) references t2(a);")
	s.tk.MustExec("drop table t1, t2, t3;")

	// foreign key constraint can reference a stored generated column.
	s.tk.MustExec("create table t1 (a int, b int generated always as (a+1) stored primary key);")
	s.tk.MustExec("create table t2 (a int, foreign key (a) references t1(b));")
	s.tk.MustExec("create table t3 (a int);")
	s.tk.MustExec("alter table t3 add foreign key (a) references t1(b);")
	s.tk.MustExec("drop table t1, t2, t3;")

	// rejected FK options on stored generated columns
	s.tk.MustGetErrCode("create table t1 (a int, b int generated always as (a+1) stored, foreign key (b) references t2(a) on update set null);", mysql.ErrWrongFKOptionForGeneratedColumn)
	s.tk.MustGetErrCode("create table t1 (a int, b int generated always as (a+1) stored, foreign key (b) references t2(a) on update cascade);", mysql.ErrWrongFKOptionForGeneratedColumn)
	s.tk.MustGetErrCode("create table t1 (a int, b int generated always as (a+1) stored, foreign key (b) references t2(a) on update set default);", mysql.ErrWrongFKOptionForGeneratedColumn)
	s.tk.MustGetErrCode("create table t1 (a int, b int generated always as (a+1) stored, foreign key (b) references t2(a) on delete set null);", mysql.ErrWrongFKOptionForGeneratedColumn)
	s.tk.MustGetErrCode("create table t1 (a int, b int generated always as (a+1) stored, foreign key (b) references t2(a) on delete set default);", mysql.ErrWrongFKOptionForGeneratedColumn)
	s.tk.MustExec("create table t2 (a int primary key);")
	s.tk.MustExec("create table t1 (a int, b int generated always as (a+1) stored);")
	s.tk.MustGetErrCode("alter table t1 add foreign key (b) references t2(a) on update set null;", mysql.ErrWrongFKOptionForGeneratedColumn)
	s.tk.MustGetErrCode("alter table t1 add foreign key (b) references t2(a) on update cascade;", mysql.ErrWrongFKOptionForGeneratedColumn)
	s.tk.MustGetErrCode("alter table t1 add foreign key (b) references t2(a) on update set default;", mysql.ErrWrongFKOptionForGeneratedColumn)
	s.tk.MustGetErrCode("alter table t1 add foreign key (b) references t2(a) on delete set null;", mysql.ErrWrongFKOptionForGeneratedColumn)
	s.tk.MustGetErrCode("alter table t1 add foreign key (b) references t2(a) on delete set default;", mysql.ErrWrongFKOptionForGeneratedColumn)
	s.tk.MustExec("drop table t1, t2;")
	// column name with uppercase characters
	s.tk.MustGetErrCode("create table t1 (A int, b int generated always as (a+1) stored, foreign key (b) references t2(a) on update set null);", mysql.ErrWrongFKOptionForGeneratedColumn)
	s.tk.MustExec("create table t2 (a int primary key);")
	s.tk.MustExec("create table t1 (A int, b int generated always as (a+1) stored);")
	s.tk.MustGetErrCode("alter table t1 add foreign key (b) references t2(a) on update set null;", mysql.ErrWrongFKOptionForGeneratedColumn)
	s.tk.MustExec("drop table t1, t2;")

	// special case: TiDB error different from MySQL 8.0
	// MySQL: ERROR 3104 (HY000): Cannot define foreign key with ON UPDATE SET NULL clause on a generated column.
	// TiDB:  ERROR 1146 (42S02): Table 'test.t2' doesn't exist
	s.tk.MustExec("create table t1 (a int, b int generated always as (a+1) stored);")
	s.tk.MustGetErrCode("alter table t1 add foreign key (b) references t2(a) on update set null;", mysql.ErrNoSuchTable)
	s.tk.MustExec("drop table t1;")

	// allowed FK options on stored generated columns
	s.tk.MustExec("create table t1 (a int primary key, b char(5));")
	s.tk.MustExec("create table t2 (a int, b int generated always as (a % 10) stored, foreign key (b) references t1(a) on update restrict);")
	s.tk.MustExec("create table t3 (a int, b int generated always as (a % 10) stored, foreign key (b) references t1(a) on update no action);")
	s.tk.MustExec("create table t4 (a int, b int generated always as (a % 10) stored, foreign key (b) references t1(a) on delete restrict);")
	s.tk.MustExec("create table t5 (a int, b int generated always as (a % 10) stored, foreign key (b) references t1(a) on delete cascade);")
	s.tk.MustExec("create table t6 (a int, b int generated always as (a % 10) stored, foreign key (b) references t1(a) on delete no action);")
	s.tk.MustExec("drop table t2,t3,t4,t5,t6;")
	s.tk.MustExec("create table t2 (a int, b int generated always as (a % 10) stored);")
	s.tk.MustExec("alter table t2 add foreign key (b) references t1(a) on update restrict;")
	s.tk.MustExec("create table t3 (a int, b int generated always as (a % 10) stored);")
	s.tk.MustExec("alter table t3 add foreign key (b) references t1(a) on update no action;")
	s.tk.MustExec("create table t4 (a int, b int generated always as (a % 10) stored);")
	s.tk.MustExec("alter table t4 add foreign key (b) references t1(a) on delete restrict;")
	s.tk.MustExec("create table t5 (a int, b int generated always as (a % 10) stored);")
	s.tk.MustExec("alter table t5 add foreign key (b) references t1(a) on delete cascade;")
	s.tk.MustExec("create table t6 (a int, b int generated always as (a % 10) stored);")
	s.tk.MustExec("alter table t6 add foreign key (b) references t1(a) on delete no action;")
	s.tk.MustExec("drop table t1,t2,t3,t4,t5,t6;")

	// rejected FK options on the base columns of a stored generated columns
	s.tk.MustExec("create table t2 (a int primary key);")
	s.tk.MustGetErrCode("create table t1 (a int, b int generated always as (a+1) stored, foreign key (a) references t2(a) on update set null);", mysql.ErrCannotAddForeign)
	s.tk.MustGetErrCode("create table t1 (a int, b int generated always as (a+1) stored, foreign key (a) references t2(a) on update cascade);", mysql.ErrCannotAddForeign)
	s.tk.MustGetErrCode("create table t1 (a int, b int generated always as (a+1) stored, foreign key (a) references t2(a) on update set default);", mysql.ErrCannotAddForeign)
	s.tk.MustGetErrCode("create table t1 (a int, b int generated always as (a+1) stored, foreign key (a) references t2(a) on delete set null);", mysql.ErrCannotAddForeign)
	s.tk.MustGetErrCode("create table t1 (a int, b int generated always as (a+1) stored, foreign key (a) references t2(a) on delete cascade);", mysql.ErrCannotAddForeign)
	s.tk.MustGetErrCode("create table t1 (a int, b int generated always as (a+1) stored, foreign key (a) references t2(a) on delete set default);", mysql.ErrCannotAddForeign)
	s.tk.MustExec("create table t1 (a int, b int generated always as (a+1) stored);")
	s.tk.MustGetErrCode("alter table t1 add foreign key (a) references t2(a) on update set null;", mysql.ErrCannotAddForeign)
	s.tk.MustGetErrCode("alter table t1 add foreign key (a) references t2(a) on update cascade;", mysql.ErrCannotAddForeign)
	s.tk.MustGetErrCode("alter table t1 add foreign key (a) references t2(a) on update set default;", mysql.ErrCannotAddForeign)
	s.tk.MustGetErrCode("alter table t1 add foreign key (a) references t2(a) on delete set null;", mysql.ErrCannotAddForeign)
	s.tk.MustGetErrCode("alter table t1 add foreign key (a) references t2(a) on delete cascade;", mysql.ErrCannotAddForeign)
	s.tk.MustGetErrCode("alter table t1 add foreign key (a) references t2(a) on delete set default;", mysql.ErrCannotAddForeign)
	s.tk.MustExec("drop table t1, t2;")

	// allowed FK options on the base columns of a stored generated columns
	s.tk.MustExec("create table t1 (a int primary key, b char(5));")
	s.tk.MustExec("create table t2 (a int, b int generated always as (a % 10) stored, foreign key (a) references t1(a) on update restrict);")
	s.tk.MustExec("create table t3 (a int, b int generated always as (a % 10) stored, foreign key (a) references t1(a) on update no action);")
	s.tk.MustExec("create table t4 (a int, b int generated always as (a % 10) stored, foreign key (a) references t1(a) on delete restrict);")
	s.tk.MustExec("create table t5 (a int, b int generated always as (a % 10) stored, foreign key (a) references t1(a) on delete no action);")
	s.tk.MustExec("drop table t2,t3,t4,t5")
	s.tk.MustExec("create table t2 (a int, b int generated always as (a % 10) stored);")
	s.tk.MustExec("alter table t2 add foreign key (a) references t1(a) on update restrict;")
	s.tk.MustExec("create table t3 (a int, b int generated always as (a % 10) stored);")
	s.tk.MustExec("alter table t3 add foreign key (a) references t1(a) on update no action;")
	s.tk.MustExec("create table t4 (a int, b int generated always as (a % 10) stored);")
	s.tk.MustExec("alter table t4 add foreign key (a) references t1(a) on delete restrict;")
	s.tk.MustExec("create table t5 (a int, b int generated always as (a % 10) stored);")
	s.tk.MustExec("alter table t5 add foreign key (a) references t1(a) on delete no action;")
	s.tk.MustExec("drop table t1,t2,t3,t4,t5;")
}

func (s *testDBSuite3) TestTruncateTable(c *C) {
	tk := testkit.NewTestKit(c, s.store)
	tk.MustExec("use test")
	tk.MustExec("create table truncate_table (c1 int, c2 int)")
	tk.MustExec("insert truncate_table values (1, 1), (2, 2)")
	ctx := tk.Se.(sessionctx.Context)
	is := domain.GetDomain(ctx).InfoSchema()
	oldTblInfo, err := is.TableByName(model.NewCIStr("test"), model.NewCIStr("truncate_table"))
	c.Assert(err, IsNil)
	oldTblID := oldTblInfo.Meta().ID

	tk.MustExec("truncate table truncate_table")

	tk.MustExec("insert truncate_table values (3, 3), (4, 4)")
	tk.MustQuery("select * from truncate_table").Check(testkit.Rows("3 3", "4 4"))

	is = domain.GetDomain(ctx).InfoSchema()
	newTblInfo, err := is.TableByName(model.NewCIStr("test"), model.NewCIStr("truncate_table"))
	c.Assert(err, IsNil)
	c.Assert(newTblInfo.Meta().ID, Greater, oldTblID)

	// Verify that the old table data has been deleted by background worker.
	tablePrefix := tablecodec.EncodeTablePrefix(oldTblID)
	hasOldTableData := true
	for i := 0; i < waitForCleanDataRound; i++ {
		err = kv.RunInNewTxn(s.store, false, func(txn kv.Transaction) error {
			it, err1 := txn.Iter(tablePrefix, nil)
			if err1 != nil {
				return err1
			}
			if !it.Valid() {
				hasOldTableData = false
			} else {
				hasOldTableData = it.Key().HasPrefix(tablePrefix)
			}
			it.Close()
			return nil
		})
		c.Assert(err, IsNil)
		if !hasOldTableData {
			break
		}
		time.Sleep(waitForCleanDataInterval)
	}
	c.Assert(hasOldTableData, IsFalse)
}

func (s *testDBSuite4) TestRenameTable(c *C) {
	isAlterTable := false
	s.testRenameTable(c, "rename table %s to %s", isAlterTable)
}

func (s *testDBSuite5) TestAlterTableRenameTable(c *C) {
	isAlterTable := true
	s.testRenameTable(c, "alter table %s rename to %s", isAlterTable)
}

func (s *testDBSuite) testRenameTable(c *C, sql string, isAlterTable bool) {
	s.tk = testkit.NewTestKit(c, s.store)
	s.tk.MustExec("use test")
	// for different databases
	s.tk.MustExec("create table t (c1 int, c2 int)")
	s.tk.MustExec("insert t values (1, 1), (2, 2)")
	ctx := s.tk.Se.(sessionctx.Context)
	is := domain.GetDomain(ctx).InfoSchema()
	oldTblInfo, err := is.TableByName(model.NewCIStr("test"), model.NewCIStr("t"))
	c.Assert(err, IsNil)
	oldTblID := oldTblInfo.Meta().ID
	s.tk.MustExec("create database test1")
	s.tk.MustExec("use test1")
	s.tk.MustExec(fmt.Sprintf(sql, "test.t", "test1.t1"))
	is = domain.GetDomain(ctx).InfoSchema()
	newTblInfo, err := is.TableByName(model.NewCIStr("test1"), model.NewCIStr("t1"))
	c.Assert(err, IsNil)
	c.Assert(newTblInfo.Meta().ID, Equals, oldTblID)
	s.tk.MustQuery("select * from t1").Check(testkit.Rows("1 1", "2 2"))
	s.tk.MustExec("use test")

	// Make sure t doesn't exist.
	s.tk.MustExec("create table t (c1 int, c2 int)")
	s.tk.MustExec("drop table t")

	// for the same database
	s.tk.MustExec("use test1")
	s.tk.MustExec(fmt.Sprintf(sql, "t1", "t2"))
	is = domain.GetDomain(ctx).InfoSchema()
	newTblInfo, err = is.TableByName(model.NewCIStr("test1"), model.NewCIStr("t2"))
	c.Assert(err, IsNil)
	c.Assert(newTblInfo.Meta().ID, Equals, oldTblID)
	s.tk.MustQuery("select * from t2").Check(testkit.Rows("1 1", "2 2"))
	isExist := is.TableExists(model.NewCIStr("test1"), model.NewCIStr("t1"))
	c.Assert(isExist, IsFalse)
	s.tk.MustQuery("show tables").Check(testkit.Rows("t2"))

	// for failure case
	failSQL := fmt.Sprintf(sql, "test_not_exist.t", "test_not_exist.t")
	if isAlterTable {
		s.tk.MustGetErrCode(failSQL, mysql.ErrNoSuchTable)
	} else {
		s.tk.MustGetErrCode(failSQL, mysql.ErrFileNotFound)
	}
	failSQL = fmt.Sprintf(sql, "test.test_not_exist", "test.test_not_exist")
	if isAlterTable {
		s.tk.MustGetErrCode(failSQL, mysql.ErrNoSuchTable)
	} else {
		s.tk.MustGetErrCode(failSQL, mysql.ErrFileNotFound)
	}
	failSQL = fmt.Sprintf(sql, "test.t_not_exist", "test_not_exist.t")
	if isAlterTable {
		s.tk.MustGetErrCode(failSQL, mysql.ErrNoSuchTable)
	} else {
		s.tk.MustGetErrCode(failSQL, mysql.ErrFileNotFound)
	}
	failSQL = fmt.Sprintf(sql, "test1.t2", "test_not_exist.t")
	s.tk.MustGetErrCode(failSQL, mysql.ErrErrorOnRename)

	s.tk.MustExec("use test1")
	s.tk.MustExec("create table if not exists t_exist (c1 int, c2 int)")
	failSQL = fmt.Sprintf(sql, "test1.t2", "test1.t_exist")
	s.tk.MustGetErrCode(failSQL, mysql.ErrTableExists)
	failSQL = fmt.Sprintf(sql, "test.t_not_exist", "test1.t_exist")
	if isAlterTable {
		s.tk.MustGetErrCode(failSQL, mysql.ErrNoSuchTable)
	} else {
		s.tk.MustGetErrCode(failSQL, mysql.ErrTableExists)
	}
	failSQL = fmt.Sprintf(sql, "test_not_exist.t", "test1.t_exist")
	if isAlterTable {
		s.tk.MustGetErrCode(failSQL, mysql.ErrNoSuchTable)
	} else {
		s.tk.MustGetErrCode(failSQL, mysql.ErrTableExists)
	}
	failSQL = fmt.Sprintf(sql, "test_not_exist.t", "test1.t_not_exist")
	if isAlterTable {
		s.tk.MustGetErrCode(failSQL, mysql.ErrNoSuchTable)
	} else {
		s.tk.MustGetErrCode(failSQL, mysql.ErrFileNotFound)
	}

	// for the same table name
	s.tk.MustExec("use test1")
	s.tk.MustExec("create table if not exists t (c1 int, c2 int)")
	s.tk.MustExec("create table if not exists t1 (c1 int, c2 int)")
	if isAlterTable {
		s.tk.MustExec(fmt.Sprintf(sql, "test1.t", "t"))
		s.tk.MustExec(fmt.Sprintf(sql, "test1.t1", "test1.T1"))
	} else {
		s.tk.MustGetErrCode(fmt.Sprintf(sql, "test1.t", "t"), mysql.ErrTableExists)
		s.tk.MustGetErrCode(fmt.Sprintf(sql, "test1.t1", "test1.T1"), mysql.ErrTableExists)
	}

	// Test rename table name too long.
	s.tk.MustGetErrCode("rename table test1.t1 to test1.txxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx", mysql.ErrTooLongIdent)
	s.tk.MustGetErrCode("alter  table test1.t1 rename to test1.txxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx", mysql.ErrTooLongIdent)

	s.tk.MustExec("drop database test1")
}

func (s *testDBSuite1) TestRenameMultiTables(c *C) {
	s.tk = testkit.NewTestKit(c, s.store)
	s.tk.MustExec("use test")
	s.tk.MustExec("create table t1(id int)")
	s.tk.MustExec("create table t2(id int)")
	// Currently it will fail only.
	sql := fmt.Sprintf("rename table t1 to t3, t2 to t4")
	_, err := s.tk.Exec(sql)
	c.Assert(err, NotNil)
	originErr := errors.Cause(err)
	c.Assert(originErr.Error(), Equals, "can't run multi schema change")

	s.tk.MustExec("drop table t1, t2")
}

func (s *testDBSuite2) TestAddNotNullColumn(c *C) {
	s.tk = testkit.NewTestKit(c, s.store)
	s.tk.MustExec("use test_db")
	// for different databases
	s.tk.MustExec("create table tnn (c1 int primary key auto_increment, c2 int)")
	s.tk.MustExec("insert tnn (c2) values (0)" + strings.Repeat(",(0)", 99))
	done := make(chan error, 1)
	testddlutil.SessionExecInGoroutine(c, s.store, "alter table tnn add column c3 int not null default 3", done)
	updateCnt := 0
out:
	for {
		select {
		case err := <-done:
			c.Assert(err, IsNil)
			break out
		default:
			s.tk.MustExec("update tnn set c2 = c2 + 1 where c1 = 99")
			updateCnt++
		}
	}
	expected := fmt.Sprintf("%d %d", updateCnt, 3)
	s.tk.MustQuery("select c2, c3 from tnn where c1 = 99").Check(testkit.Rows(expected))

	s.tk.MustExec("drop table tnn")
}

func (s *testDBSuite3) TestGeneratedColumnDDL(c *C) {
	s.tk = testkit.NewTestKit(c, s.store)
	s.tk.MustExec("use test")

	// Check create table with virtual and stored generated columns.
	s.tk.MustExec(`CREATE TABLE test_gv_ddl(a int, b int as (a+8) virtual, c int as (b + 2) stored)`)

	// Check desc table with virtual and stored generated columns.
	result := s.tk.MustQuery(`DESC test_gv_ddl`)
	result.Check(testkit.Rows(`a int(11) YES  <nil> `, `b int(11) YES  <nil> VIRTUAL GENERATED`, `c int(11) YES  <nil> STORED GENERATED`))

	// Check show create table with virtual and stored generated columns.
	result = s.tk.MustQuery(`show create table test_gv_ddl`)
	result.Check(testkit.Rows(
		"test_gv_ddl CREATE TABLE `test_gv_ddl` (\n  `a` int(11) DEFAULT NULL,\n  `b` int(11) GENERATED ALWAYS AS (`a` + 8) VIRTUAL,\n  `c` int(11) GENERATED ALWAYS AS (`b` + 2) STORED\n) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin",
	))

	// Check generated expression with blanks.
	s.tk.MustExec("create table table_with_gen_col_blanks (a int, b char(20) as (cast( \r\n\t a \r\n\tas  char)), c int as (a+100))")
	result = s.tk.MustQuery(`show create table table_with_gen_col_blanks`)
	result.Check(testkit.Rows("table_with_gen_col_blanks CREATE TABLE `table_with_gen_col_blanks` (\n" +
		"  `a` int(11) DEFAULT NULL,\n" +
		"  `b` char(20) GENERATED ALWAYS AS (cast(`a` as char)) VIRTUAL,\n" +
		"  `c` int(11) GENERATED ALWAYS AS (`a` + 100) VIRTUAL\n" +
		") ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin"))

	// Check generated expression with charset latin1 ("latin1" != mysql.DefaultCharset).
	s.tk.MustExec("create table table_with_gen_col_latin1 (a int, b char(20) as (cast( \r\n\t a \r\n\tas  char charset latin1)), c int as (a+100))")
	result = s.tk.MustQuery(`show create table table_with_gen_col_latin1`)
	result.Check(testkit.Rows("table_with_gen_col_latin1 CREATE TABLE `table_with_gen_col_latin1` (\n" +
		"  `a` int(11) DEFAULT NULL,\n" +
		"  `b` char(20) GENERATED ALWAYS AS (cast(`a` as char charset latin1)) VIRTUAL,\n" +
		"  `c` int(11) GENERATED ALWAYS AS (`a` + 100) VIRTUAL\n" +
		") ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin"))

	// Check generated expression with string (issue 9457).
	s.tk.MustExec("create table table_with_gen_col_string (first_name varchar(10), last_name varchar(10), full_name varchar(255) AS (CONCAT(first_name,' ',last_name)))")
	result = s.tk.MustQuery(`show create table table_with_gen_col_string`)
	result.Check(testkit.Rows("table_with_gen_col_string CREATE TABLE `table_with_gen_col_string` (\n" +
		"  `first_name` varchar(10) DEFAULT NULL,\n" +
		"  `last_name` varchar(10) DEFAULT NULL,\n" +
		"  `full_name` varchar(255) GENERATED ALWAYS AS (concat(`first_name`, ' ', `last_name`)) VIRTUAL\n" +
		") ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin"))

	s.tk.MustExec("alter table table_with_gen_col_string modify column full_name varchar(255) GENERATED ALWAYS AS (CONCAT(last_name,' ' ,first_name) ) VIRTUAL")
	result = s.tk.MustQuery(`show create table table_with_gen_col_string`)
	result.Check(testkit.Rows("table_with_gen_col_string CREATE TABLE `table_with_gen_col_string` (\n" +
		"  `first_name` varchar(10) DEFAULT NULL,\n" +
		"  `last_name` varchar(10) DEFAULT NULL,\n" +
		"  `full_name` varchar(255) GENERATED ALWAYS AS (concat(`last_name`, ' ', `first_name`)) VIRTUAL\n" +
		") ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin"))

	genExprTests := []struct {
		stmt string
		err  int
	}{
		// Drop/rename columns dependent by other column.
		{`alter table test_gv_ddl drop column a`, mysql.ErrDependentByGeneratedColumn},
		{`alter table test_gv_ddl change column a anew int`, mysql.ErrBadField},

		// Modify/change stored status of generated columns.
		{`alter table test_gv_ddl modify column b bigint`, mysql.ErrUnsupportedOnGeneratedColumn},
		{`alter table test_gv_ddl change column c cnew bigint as (a+100)`, mysql.ErrUnsupportedOnGeneratedColumn},

		// Modify/change generated columns breaking prior.
		{`alter table test_gv_ddl modify column b int as (c+100)`, mysql.ErrGeneratedColumnNonPrior},
		{`alter table test_gv_ddl change column b bnew int as (c+100)`, mysql.ErrGeneratedColumnNonPrior},

		// Refer not exist columns in generation expression.
		{`create table test_gv_ddl_bad (a int, b int as (c+8))`, mysql.ErrBadField},

		// Refer generated columns non prior.
		{`create table test_gv_ddl_bad (a int, b int as (c+1), c int as (a+1))`, mysql.ErrGeneratedColumnNonPrior},

		// Virtual generated columns cannot be primary key.
		{`create table test_gv_ddl_bad (a int, b int, c int as (a+b) primary key)`, mysql.ErrUnsupportedOnGeneratedColumn},
		{`create table test_gv_ddl_bad (a int, b int, c int as (a+b), primary key(c))`, mysql.ErrUnsupportedOnGeneratedColumn},
		{`create table test_gv_ddl_bad (a int, b int, c int as (a+b), primary key(a, c))`, mysql.ErrUnsupportedOnGeneratedColumn},

		// Add stored generated column through alter table.
		{`alter table test_gv_ddl add column d int as (b+2) stored`, mysql.ErrUnsupportedOnGeneratedColumn},
		{`alter table test_gv_ddl modify column b int as (a + 8) stored`, mysql.ErrUnsupportedOnGeneratedColumn},
	}
	for _, tt := range genExprTests {
		s.tk.MustGetErrCode(tt.stmt, tt.err)
	}

	// Check alter table modify/change generated column.
	modStoredColErrMsg := "[ddl:3106]'modifying a stored column' is not supported for generated columns."
	_, err := s.tk.Exec(`alter table test_gv_ddl modify column c bigint as (b+200) stored`)
	c.Assert(err, NotNil)
	c.Assert(err.Error(), Equals, modStoredColErrMsg)

	result = s.tk.MustQuery(`DESC test_gv_ddl`)
	result.Check(testkit.Rows(`a int(11) YES  <nil> `, `b int(11) YES  <nil> VIRTUAL GENERATED`, `c int(11) YES  <nil> STORED GENERATED`))

	s.tk.MustExec(`alter table test_gv_ddl change column b b bigint as (a+100) virtual`)
	result = s.tk.MustQuery(`DESC test_gv_ddl`)
	result.Check(testkit.Rows(`a int(11) YES  <nil> `, `b bigint(20) YES  <nil> VIRTUAL GENERATED`, `c int(11) YES  <nil> STORED GENERATED`))

	s.tk.MustExec(`alter table test_gv_ddl change column c cnew bigint`)
	result = s.tk.MustQuery(`DESC test_gv_ddl`)
	result.Check(testkit.Rows(`a int(11) YES  <nil> `, `b bigint(20) YES  <nil> VIRTUAL GENERATED`, `cnew bigint(20) YES  <nil> `))
}

func (s *testDBSuite4) TestComment(c *C) {
	s.tk = testkit.NewTestKit(c, s.store)
	s.tk.MustExec("use " + s.schemaName)
	s.tk.MustExec("drop table if exists ct, ct1")

	validComment := strings.Repeat("a", 1024)
	invalidComment := strings.Repeat("b", 1025)

	s.tk.MustExec("create table ct (c int, d int, e int, key (c) comment '" + validComment + "')")
	s.tk.MustExec("create index i on ct (d) comment '" + validComment + "'")
	s.tk.MustExec("alter table ct add key (e) comment '" + validComment + "'")

	s.tk.MustGetErrCode("create table ct1 (c int, key (c) comment '"+invalidComment+"')", mysql.ErrTooLongIndexComment)
	s.tk.MustGetErrCode("create index i1 on ct (d) comment '"+invalidComment+"b"+"'", mysql.ErrTooLongIndexComment)
	s.tk.MustGetErrCode("alter table ct add key (e) comment '"+invalidComment+"'", mysql.ErrTooLongIndexComment)

	s.tk.MustExec("set @@sql_mode=''")
	s.tk.MustExec("create table ct1 (c int, d int, e int, key (c) comment '" + invalidComment + "')")
	c.Assert(s.tk.Se.GetSessionVars().StmtCtx.WarningCount(), Equals, uint16(1))
	s.tk.MustQuery("show warnings").Check(testutil.RowsWithSep("|", "Warning|1688|Comment for index 'c' is too long (max = 1024)"))
	s.tk.MustExec("create index i1 on ct1 (d) comment '" + invalidComment + "b" + "'")
	c.Assert(s.tk.Se.GetSessionVars().StmtCtx.WarningCount(), Equals, uint16(1))
	s.tk.MustQuery("show warnings").Check(testutil.RowsWithSep("|", "Warning|1688|Comment for index 'i1' is too long (max = 1024)"))
	s.tk.MustExec("alter table ct1 add key (e) comment '" + invalidComment + "'")
	c.Assert(s.tk.Se.GetSessionVars().StmtCtx.WarningCount(), Equals, uint16(1))
	s.tk.MustQuery("show warnings").Check(testutil.RowsWithSep("|", "Warning|1688|Comment for index 'e' is too long (max = 1024)"))

	s.tk.MustExec("drop table if exists ct, ct1")
}

func (s *testDBSuite4) TestRebaseAutoID(c *C) {
	c.Assert(failpoint.Enable("github.com/pingcap/tidb/meta/autoid/mockAutoIDChange", `return(true)`), IsNil)
	defer func() {
		c.Assert(failpoint.Disable("github.com/pingcap/tidb/meta/autoid/mockAutoIDChange"), IsNil)
	}()
	s.tk = testkit.NewTestKit(c, s.store)
	s.tk.MustExec("use " + s.schemaName)

	s.tk.MustExec("drop database if exists tidb;")
	s.tk.MustExec("create database tidb;")
	s.tk.MustExec("use tidb;")
	s.tk.MustExec("create table tidb.test (a int auto_increment primary key, b int);")
	s.tk.MustExec("insert tidb.test values (null, 1);")
	s.tk.MustQuery("select * from tidb.test").Check(testkit.Rows("1 1"))
	s.tk.MustExec("alter table tidb.test auto_increment = 6000;")
	s.tk.MustExec("insert tidb.test values (null, 1);")
	s.tk.MustQuery("select * from tidb.test").Check(testkit.Rows("1 1", "6000 1"))
	s.tk.MustExec("alter table tidb.test auto_increment = 5;")
	s.tk.MustExec("insert tidb.test values (null, 1);")
	s.tk.MustQuery("select * from tidb.test").Check(testkit.Rows("1 1", "6000 1", "11000 1"))

	// Current range for table test is [11000, 15999].
	// Though it does not have a tuple "a = 15999", its global next auto increment id should be 16000.
	// Anyway it is not compatible with MySQL.
	s.tk.MustExec("alter table tidb.test auto_increment = 12000;")
	s.tk.MustExec("insert tidb.test values (null, 1);")
	s.tk.MustQuery("select * from tidb.test").Check(testkit.Rows("1 1", "6000 1", "11000 1", "16000 1"))

	s.tk.MustExec("create table tidb.test2 (a int);")
	s.tk.MustGetErrCode("alter table tidb.test2 add column b int auto_increment key, auto_increment=10;", mysql.ErrUnsupportedDDLOperation)
}

func (s *testDBSuite5) TestCheckColumnDefaultValue(c *C) {
	s.tk = testkit.NewTestKit(c, s.store)
	s.tk.MustExec("use test;")
	s.tk.MustExec("drop table if exists text_default_text;")
	s.tk.MustGetErrCode("create table text_default_text(c1 text not null default '');", mysql.ErrBlobCantHaveDefault)
	s.tk.MustGetErrCode("create table text_default_text(c1 text not null default 'scds');", mysql.ErrBlobCantHaveDefault)

	s.tk.MustExec("drop table if exists text_default_json;")
	s.tk.MustGetErrCode("create table text_default_json(c1 json not null default '');", mysql.ErrBlobCantHaveDefault)
	s.tk.MustGetErrCode("create table text_default_json(c1 json not null default 'dfew555');", mysql.ErrBlobCantHaveDefault)

	s.tk.MustExec("drop table if exists text_default_blob;")
	s.tk.MustGetErrCode("create table text_default_blob(c1 blob not null default '');", mysql.ErrBlobCantHaveDefault)
	s.tk.MustGetErrCode("create table text_default_blob(c1 blob not null default 'scds54');", mysql.ErrBlobCantHaveDefault)

	s.tk.MustExec("set sql_mode='';")
	s.tk.MustExec("create table text_default_text(c1 text not null default '');")
	s.tk.MustQuery(`show create table text_default_text`).Check(testutil.RowsWithSep("|",
		"text_default_text CREATE TABLE `text_default_text` (\n"+
			"  `c1` text NOT NULL\n"+
			") ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin",
	))
	ctx := s.tk.Se.(sessionctx.Context)
	is := domain.GetDomain(ctx).InfoSchema()
	tblInfo, err := is.TableByName(model.NewCIStr("test"), model.NewCIStr("text_default_text"))
	c.Assert(err, IsNil)
	c.Assert(tblInfo.Meta().Columns[0].DefaultValue, Equals, "")

	s.tk.MustExec("create table text_default_blob(c1 blob not null default '');")
	s.tk.MustQuery(`show create table text_default_blob`).Check(testutil.RowsWithSep("|",
		"text_default_blob CREATE TABLE `text_default_blob` (\n"+
			"  `c1` blob NOT NULL\n"+
			") ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin",
	))
	is = domain.GetDomain(ctx).InfoSchema()
	tblInfo, err = is.TableByName(model.NewCIStr("test"), model.NewCIStr("text_default_blob"))
	c.Assert(err, IsNil)
	c.Assert(tblInfo.Meta().Columns[0].DefaultValue, Equals, "")

	s.tk.MustExec("create table text_default_json(c1 json not null default '');")
	s.tk.MustQuery(`show create table text_default_json`).Check(testutil.RowsWithSep("|",
		"text_default_json CREATE TABLE `text_default_json` (\n"+
			"  `c1` json NOT NULL DEFAULT 'null'\n"+
			") ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin",
	))
	is = domain.GetDomain(ctx).InfoSchema()
	tblInfo, err = is.TableByName(model.NewCIStr("test"), model.NewCIStr("text_default_json"))
	c.Assert(err, IsNil)
	c.Assert(tblInfo.Meta().Columns[0].DefaultValue, Equals, `null`)
}

func (s *testDBSuite1) TestCharacterSetInColumns(c *C) {
	s.tk = testkit.NewTestKit(c, s.store)
	s.tk.MustExec("create database varchar_test;")
	defer s.tk.MustExec("drop database varchar_test;")
	s.tk.MustExec("use varchar_test")
	s.tk.MustExec("create table t (c1 int, s1 varchar(10), s2 text)")
	s.tk.MustQuery("select count(*) from information_schema.columns where table_schema = 'varchar_test' and character_set_name != 'utf8mb4'").Check(testkit.Rows("0"))
	s.tk.MustQuery("select count(*) from information_schema.columns where table_schema = 'varchar_test' and character_set_name = 'utf8mb4'").Check(testkit.Rows("2"))

	s.tk.MustExec("create table t1(id int) charset=UTF8;")
	s.tk.MustExec("create table t2(id int) charset=BINARY;")
	s.tk.MustExec("create table t3(id int) charset=LATIN1;")
	s.tk.MustExec("create table t4(id int) charset=ASCII;")
	s.tk.MustExec("create table t5(id int) charset=UTF8MB4;")

	s.tk.MustExec("create table t11(id int) charset=utf8;")
	s.tk.MustExec("create table t12(id int) charset=binary;")
	s.tk.MustExec("create table t13(id int) charset=latin1;")
	s.tk.MustExec("create table t14(id int) charset=ascii;")
	s.tk.MustExec("create table t15(id int) charset=utf8mb4;")
}

func (s *testDBSuite2) TestAddNotNullColumnWhileInsertOnDupUpdate(c *C) {
	tk1 := testkit.NewTestKit(c, s.store)
	tk1.MustExec("use " + s.schemaName)
	tk2 := testkit.NewTestKit(c, s.store)
	tk2.MustExec("use " + s.schemaName)
	closeCh := make(chan bool)
	wg := new(sync.WaitGroup)
	wg.Add(1)
	tk1.MustExec("create table nn (a int primary key, b int)")
	tk1.MustExec("insert nn values (1, 1)")
	var tk2Err error
	go func() {
		defer wg.Done()
		for {
			select {
			case <-closeCh:
				return
			default:
			}
			_, tk2Err = tk2.Exec("insert nn (a, b) values (1, 1) on duplicate key update a = 1, b = values(b) + 1")
			if tk2Err != nil {
				return
			}
		}
	}()
	tk1.MustExec("alter table nn add column c int not null default 3 after a")
	close(closeCh)
	wg.Wait()
	c.Assert(tk2Err, IsNil)
	tk1.MustQuery("select * from nn").Check(testkit.Rows("1 3 2"))
}

func (s *testDBSuite3) TestColumnModifyingDefinition(c *C) {
	s.tk = testkit.NewTestKit(c, s.store)
	s.tk.MustExec("use test")
	s.tk.MustExec("drop table if exists test2;")
	s.tk.MustExec("create table test2 (c1 int, c2 int, c3 int default 1, index (c1));")
	s.tk.MustExec("alter table test2 change c2 a int not null;")
	ctx := s.tk.Se.(sessionctx.Context)
	is := domain.GetDomain(ctx).InfoSchema()
	t, err := is.TableByName(model.NewCIStr("test"), model.NewCIStr("test2"))
	c.Assert(err, IsNil)
	var c2 *table.Column
	for _, col := range t.Cols() {
		if col.Name.L == "a" {
			c2 = col
		}
	}
	c.Assert(mysql.HasNotNullFlag(c2.Flag), IsTrue)

	s.tk.MustExec("drop table if exists test2;")
	s.tk.MustExec("create table test2 (c1 int, c2 int, c3 int default 1, index (c1));")
	s.tk.MustExec("insert into test2(c2) values (null);")
	s.tk.MustGetErrCode("alter table test2 change c2 a int not null", mysql.ErrInvalidUseOfNull)
	s.tk.MustGetErrCode("alter table test2 change c1 a1 bigint not null;", mysql.WarnDataTruncated)
}

func (s *testDBSuite4) TestCheckTooBigFieldLength(c *C) {
	s.tk = testkit.NewTestKit(c, s.store)
	s.tk.MustExec("use test")
	s.tk.MustExec("drop table if exists tr_01;")
	s.tk.MustExec("create table tr_01 (id int, name varchar(20000), purchased date )  default charset=utf8 collate=utf8_bin;")

	s.tk.MustExec("drop table if exists tr_02;")
	s.tk.MustExec("create table tr_02 (id int, name varchar(16000), purchased date )  default charset=utf8mb4 collate=utf8mb4_bin;")

	s.tk.MustExec("drop table if exists tr_03;")
	s.tk.MustExec("create table tr_03 (id int, name varchar(65534), purchased date ) default charset=latin1;")

	s.tk.MustExec("drop table if exists tr_04;")
	s.tk.MustExec("create table tr_04 (a varchar(20000) ) default charset utf8;")
	s.tk.MustGetErrCode("alter table tr_04 add column b varchar(20000) charset utf8mb4;", mysql.ErrTooBigFieldlength)
	s.tk.MustGetErrCode("alter table tr_04 convert to character set utf8mb4;", mysql.ErrTooBigFieldlength)
	s.tk.MustGetErrCode("create table tr (id int, name varchar(30000), purchased date )  default charset=utf8 collate=utf8_bin;", mysql.ErrTooBigFieldlength)
	s.tk.MustGetErrCode("create table tr (id int, name varchar(20000) charset utf8mb4, purchased date ) default charset=utf8 collate=utf8_bin;", mysql.ErrTooBigFieldlength)
	s.tk.MustGetErrCode("create table tr (id int, name varchar(65536), purchased date ) default charset=latin1;", mysql.ErrTooBigFieldlength)

	s.tk.MustExec("drop table if exists tr_05;")
	s.tk.MustExec("create table tr_05 (a varchar(16000) charset utf8);")
	s.tk.MustExec("alter table tr_05 modify column a varchar(16000) charset utf8;")
	s.tk.MustExec("alter table tr_05 modify column a varchar(16000) charset utf8mb4;")
}

func (s *testDBSuite5) TestCheckConvertToCharacter(c *C) {
	s.tk = testkit.NewTestKit(c, s.store)
	s.tk.MustExec("use test")
	s.tk.MustExec("drop table if exists t")
	defer s.tk.MustExec("drop table t")
	s.tk.MustExec("create table t(a varchar(10) charset binary);")
	ctx := s.tk.Se.(sessionctx.Context)
	is := domain.GetDomain(ctx).InfoSchema()
	t, err := is.TableByName(model.NewCIStr("test"), model.NewCIStr("t"))
	c.Assert(err, IsNil)
	s.tk.MustGetErrCode("alter table t modify column a varchar(10) charset utf8 collate utf8_bin", mysql.ErrUnsupportedDDLOperation)
	s.tk.MustGetErrCode("alter table t modify column a varchar(10) charset utf8mb4 collate utf8mb4_bin", mysql.ErrUnsupportedDDLOperation)
	s.tk.MustGetErrCode("alter table t modify column a varchar(10) charset latin1 collate latin1_bin", mysql.ErrUnsupportedDDLOperation)
	c.Assert(t.Cols()[0].Charset, Equals, "binary")
}

func (s *testDBSuite5) TestModifyColumnRollBack(c *C) {
	s.tk = testkit.NewTestKit(c, s.store)
	s.mustExec(c, "use test_db")
	s.mustExec(c, "drop table if exists t1")
	s.mustExec(c, "create table t1 (c1 int, c2 int, c3 int default 1, index (c1));")

	var c2 *table.Column
	var checkErr error
	hook := &ddl.TestDDLCallback{}
	hook.OnJobUpdatedExported = func(job *model.Job) {
		if checkErr != nil {
			return
		}

		t := s.testGetTable(c, "t1")
		for _, col := range t.Cols() {
			if col.Name.L == "c2" {
				c2 = col
			}
		}
		if mysql.HasPreventNullInsertFlag(c2.Flag) {
			s.tk.MustGetErrCode("insert into t1(c2) values (null);", mysql.ErrBadNull)
		}

		hookCtx := mock.NewContext()
		hookCtx.Store = s.store
		err := hookCtx.NewTxn(context.Background())
		if err != nil {
			checkErr = errors.Trace(err)
			return
		}

		jobIDs := []int64{job.ID}
		txn, err := hookCtx.Txn(true)
		if err != nil {
			checkErr = errors.Trace(err)
			return
		}
		errs, err := admin.CancelJobs(txn, jobIDs)
		if err != nil {
			checkErr = errors.Trace(err)
			return
		}
		// It only tests cancel one DDL job.
		if errs[0] != nil {
			checkErr = errors.Trace(errs[0])
			return
		}

		txn, err = hookCtx.Txn(true)
		if err != nil {
			checkErr = errors.Trace(err)
			return
		}
		err = txn.Commit(context.Background())
		if err != nil {
			checkErr = errors.Trace(err)
		}
	}

	originalHook := s.dom.DDL().GetHook()
	s.dom.DDL().(ddl.DDLForTest).SetHook(hook)
	done := make(chan error, 1)
	go backgroundExec(s.store, "alter table t1 change c2 c2 bigint not null;", done)
	ticker := time.NewTicker(s.lease / 2)
	defer ticker.Stop()
LOOP:
	for {
		select {
		case err := <-done:
			c.Assert(err, NotNil)
			c.Assert(err.Error(), Equals, "[ddl:8214]Cancelled DDL job")
			break LOOP
		case <-ticker.C:
			s.mustExec(c, "insert into t1(c2) values (null);")
		}
	}

	t := s.testGetTable(c, "t1")
	for _, col := range t.Cols() {
		if col.Name.L == "c2" {
			c2 = col
		}
	}
	c.Assert(mysql.HasNotNullFlag(c2.Flag), IsFalse)
	s.dom.DDL().(ddl.DDLForTest).SetHook(originalHook)
	s.mustExec(c, "drop table t1")
}

func (s *testDBSuite1) TestModifyColumnNullToNotNull(c *C) {
	s.tk = testkit.NewTestKit(c, s.store)
	tk2 := testkit.NewTestKit(c, s.store)
	tk2.MustExec("use test_db")
	s.mustExec(c, "use test_db")
	s.mustExec(c, "drop table if exists t1")
	s.mustExec(c, "create table t1 (c1 int, c2 int);")

	tbl := s.testGetTable(c, "t1")
	getModifyColumn := func() *table.Column {
		t := s.testGetTable(c, "t1")
		for _, col := range t.Cols() {
			if col.Name.L == "c2" {
				return col
			}
		}
		return nil
	}

	originalHook := s.dom.DDL().GetHook()
	defer s.dom.DDL().(ddl.DDLForTest).SetHook(originalHook)

	// Check insert null before job first update.
	times := 0
	hook := &ddl.TestDDLCallback{}
	s.tk.MustExec("delete from t1")
	var checkErr error
	hook.OnJobRunBeforeExported = func(job *model.Job) {
		if tbl.Meta().ID != job.TableID {
			return
		}
		if times == 0 {
			_, checkErr = tk2.Exec("insert into t1 values ();")
		}
		times++
	}
	s.dom.DDL().(ddl.DDLForTest).SetHook(hook)
	_, err := s.tk.Exec("alter table t1 change c2 c2 int not null;")
	c.Assert(checkErr, IsNil)
	c.Assert(err, NotNil)
	c.Assert(err.Error(), Equals, "[ddl:1138]Invalid use of NULL value")
	s.tk.MustQuery("select * from t1").Check(testkit.Rows("<nil> <nil>"))

	// Check insert error when column has PreventNullInsertFlag.
	s.tk.MustExec("delete from t1")
	hook.OnJobRunBeforeExported = func(job *model.Job) {
		if tbl.Meta().ID != job.TableID {
			return
		}
		if job.State != model.JobStateRunning {
			return
		}
		// now c2 has PreventNullInsertFlag, an error is expected.
		_, checkErr = tk2.Exec("insert into t1 values ();")
	}
	s.dom.DDL().(ddl.DDLForTest).SetHook(hook)
	s.tk.MustExec("alter table t1 change c2 c2 bigint not null;")
	c.Assert(checkErr.Error(), Equals, "[table:1048]Column 'c2' cannot be null")

	c2 := getModifyColumn()
	c.Assert(mysql.HasNotNullFlag(c2.Flag), IsTrue)
	c.Assert(mysql.HasPreventNullInsertFlag(c2.Flag), IsFalse)
	_, err = s.tk.Exec("insert into t1 values ();")
	c.Assert(err, NotNil)
	c.Assert(err.Error(), Equals, "[table:1364]Field 'c2' doesn't have a default value")
}

func (s *testDBSuite2) TestTransactionOnAddDropColumn(c *C) {
	s.tk = testkit.NewTestKit(c, s.store)
	s.mustExec(c, "use test_db")
	s.mustExec(c, "drop table if exists t1")
	s.mustExec(c, "create table t1 (a int, b int);")
	s.mustExec(c, "create table t2 (a int, b int);")
	s.mustExec(c, "insert into t2 values (2,0)")

	transactions := [][]string{
		{
			"begin",
			"insert into t1 set a=1",
			"update t1 set b=1 where a=1",
			"commit",
		},
		{
			"begin",
			"insert into t1 select a,b from t2",
			"update t1 set b=2 where a=2",
			"commit",
		},
	}

	originHook := s.dom.DDL().GetHook()
	defer s.dom.DDL().(ddl.DDLForTest).SetHook(originHook)
	hook := &ddl.TestDDLCallback{}
	hook.OnJobRunBeforeExported = func(job *model.Job) {
		switch job.SchemaState {
		case model.StateWriteOnly, model.StateWriteReorganization, model.StateDeleteOnly, model.StateDeleteReorganization:
		default:
			return
		}
		// do transaction.
		for _, transaction := range transactions {
			for _, sql := range transaction {
				s.mustExec(c, sql)
			}
		}
	}
	s.dom.DDL().(ddl.DDLForTest).SetHook(hook)
	done := make(chan error, 1)
	// test transaction on add column.
	go backgroundExec(s.store, "alter table t1 add column c int not null after a", done)
	err := <-done
	c.Assert(err, IsNil)
	s.tk.MustQuery("select a,b from t1 order by a").Check(testkit.Rows("1 1", "1 1", "1 1", "2 2", "2 2", "2 2"))
	s.mustExec(c, "delete from t1")

	// test transaction on drop column.
	go backgroundExec(s.store, "alter table t1 drop column c", done)
	err = <-done
	c.Assert(err, IsNil)
	s.tk.MustQuery("select a,b from t1 order by a").Check(testkit.Rows("1 1", "1 1", "1 1", "2 2", "2 2", "2 2"))
}

func (s *testDBSuite3) TestTransactionWithWriteOnlyColumn(c *C) {
	s.tk = testkit.NewTestKit(c, s.store)
	s.mustExec(c, "use test_db")
	s.mustExec(c, "drop table if exists t1")
	s.mustExec(c, "create table t1 (a int key);")

	transactions := [][]string{
		{
			"begin",
			"insert into t1 set a=1",
			"update t1 set a=2 where a=1",
			"commit",
		},
	}

	originHook := s.dom.DDL().GetHook()
	defer s.dom.DDL().(ddl.DDLForTest).SetHook(originHook)
	hook := &ddl.TestDDLCallback{}
	hook.OnJobRunBeforeExported = func(job *model.Job) {
		switch job.SchemaState {
		case model.StateWriteOnly:
		default:
			return
		}
		// do transaction.
		for _, transaction := range transactions {
			for _, sql := range transaction {
				s.mustExec(c, sql)
			}
		}
	}
	s.dom.DDL().(ddl.DDLForTest).SetHook(hook)
	done := make(chan error, 1)
	// test transaction on add column.
	go backgroundExec(s.store, "alter table t1 add column c int not null", done)
	err := <-done
	c.Assert(err, IsNil)
	s.tk.MustQuery("select a from t1").Check(testkit.Rows("2"))
	s.mustExec(c, "delete from t1")

	// test transaction on drop column.
	go backgroundExec(s.store, "alter table t1 drop column c", done)
	err = <-done
	c.Assert(err, IsNil)
	s.tk.MustQuery("select a from t1").Check(testkit.Rows("2"))
}

func (s *testDBSuite4) TestAddColumn2(c *C) {
	s.tk = testkit.NewTestKit(c, s.store)
	s.mustExec(c, "use test_db")
	s.mustExec(c, "drop table if exists t1")
	s.mustExec(c, "create table t1 (a int key, b int);")
	defer s.mustExec(c, "drop table if exists t1, t2")

	originHook := s.dom.DDL().GetHook()
	defer s.dom.DDL().(ddl.DDLForTest).SetHook(originHook)
	hook := &ddl.TestDDLCallback{}
	var writeOnlyTable table.Table
	hook.OnJobRunBeforeExported = func(job *model.Job) {
		if job.SchemaState == model.StateWriteOnly {
			writeOnlyTable, _ = s.dom.InfoSchema().TableByID(job.TableID)
		}
	}
	s.dom.DDL().(ddl.DDLForTest).SetHook(hook)
	done := make(chan error, 1)
	// test transaction on add column.
	go backgroundExec(s.store, "alter table t1 add column c int not null", done)
	err := <-done
	c.Assert(err, IsNil)

	s.mustExec(c, "insert into t1 values (1,1,1)")
	s.tk.MustQuery("select a,b,c from t1").Check(testkit.Rows("1 1 1"))

	// mock for outdated tidb update record.
	c.Assert(writeOnlyTable, NotNil)
	ctx := context.Background()
	err = s.tk.Se.NewTxn(ctx)
	c.Assert(err, IsNil)
	oldRow, err := writeOnlyTable.RowWithCols(s.tk.Se, 1, writeOnlyTable.WritableCols())
	c.Assert(err, IsNil)
	c.Assert(len(oldRow), Equals, 3)
	err = writeOnlyTable.RemoveRecord(s.tk.Se, 1, oldRow)
	c.Assert(err, IsNil)
	_, err = writeOnlyTable.AddRecord(s.tk.Se, types.MakeDatums(oldRow[0].GetInt64(), 2, oldRow[2].GetInt64()), table.IsUpdate)
	c.Assert(err, IsNil)
	err = s.tk.Se.StmtCommit()
	c.Assert(err, IsNil)
	err = s.tk.Se.CommitTxn(ctx)
	c.Assert(err, IsNil)

	s.tk.MustQuery("select a,b,c from t1").Check(testkit.Rows("1 2 1"))

	// Test for _tidb_rowid
	var re *testkit.Result
	s.mustExec(c, "create table t2 (a int);")
	hook.OnJobRunBeforeExported = func(job *model.Job) {
		if job.SchemaState != model.StateWriteOnly {
			return
		}
		// allow write _tidb_rowid first
		s.mustExec(c, "set @@tidb_opt_write_row_id=1")
		s.mustExec(c, "begin")
		s.mustExec(c, "insert into t2 (a,_tidb_rowid) values (1,2);")
		re = s.tk.MustQuery(" select a,_tidb_rowid from t2;")
		s.mustExec(c, "commit")

	}
	s.dom.DDL().(ddl.DDLForTest).SetHook(hook)

	go backgroundExec(s.store, "alter table t2 add column b int not null default 3", done)
	err = <-done
	c.Assert(err, IsNil)
	re.Check(testkit.Rows("1 2"))
	s.tk.MustQuery("select a,b,_tidb_rowid from t2").Check(testkit.Rows("1 3 2"))
}

func (s *testDBSuite4) TestIfNotExists(c *C) {
	s.tk = testkit.NewTestKit(c, s.store)
	s.tk.MustExec("use test_db")
	s.mustExec(c, "drop table if exists t1")
	s.mustExec(c, "create table t1 (a int key);")

	// ADD COLUMN
	sql := "alter table t1 add column b int"
	s.mustExec(c, sql)
	s.tk.MustGetErrCode(sql, mysql.ErrDupFieldName)
	s.mustExec(c, "alter table t1 add column if not exists b int")
	c.Assert(s.tk.Se.GetSessionVars().StmtCtx.WarningCount(), Equals, uint16(1))
	s.tk.MustQuery("show warnings").Check(testutil.RowsWithSep("|", "Note|1060|Duplicate column name 'b'"))

	// ADD INDEX
	sql = "alter table t1 add index idx_b (b)"
	s.mustExec(c, sql)
	s.tk.MustGetErrCode(sql, mysql.ErrDupKeyName)
	s.mustExec(c, "alter table t1 add index if not exists idx_b (b)")
	c.Assert(s.tk.Se.GetSessionVars().StmtCtx.WarningCount(), Equals, uint16(1))
	s.tk.MustQuery("show warnings").Check(testutil.RowsWithSep("|", "Note|1061|index already exist idx_b"))

	// CREATE INDEX
	sql = "create index idx_b on t1 (b)"
	s.tk.MustGetErrCode(sql, mysql.ErrDupKeyName)
	s.mustExec(c, "create index if not exists idx_b on t1 (b)")
	c.Assert(s.tk.Se.GetSessionVars().StmtCtx.WarningCount(), Equals, uint16(1))
	s.tk.MustQuery("show warnings").Check(testutil.RowsWithSep("|", "Note|1061|index already exist idx_b"))

	// ADD PARTITION
	s.mustExec(c, "drop table if exists t2")
	s.mustExec(c, "create table t2 (a int key) partition by range(a) (partition p0 values less than (10), partition p1 values less than (20))")
	sql = "alter table t2 add partition (partition p2 values less than (30))"
	s.mustExec(c, sql)
	s.tk.MustGetErrCode(sql, mysql.ErrSameNamePartition)
	s.mustExec(c, "alter table t2 add partition if not exists (partition p2 values less than (30))")
	c.Assert(s.tk.Se.GetSessionVars().StmtCtx.WarningCount(), Equals, uint16(1))
	s.tk.MustQuery("show warnings").Check(testutil.RowsWithSep("|", "Note|1517|Duplicate partition name p2"))
}

func (s *testDBSuite4) TestIfExists(c *C) {
	s.tk = testkit.NewTestKit(c, s.store)
	s.tk.MustExec("use test_db")
	s.mustExec(c, "drop table if exists t1")
	s.mustExec(c, "create table t1 (a int key, b int);")

	// DROP COLUMN
	sql := "alter table t1 drop column b"
	s.mustExec(c, sql)
	s.tk.MustGetErrCode(sql, mysql.ErrCantDropFieldOrKey)
	s.mustExec(c, "alter table t1 drop column if exists b") // only `a` exists now
	c.Assert(s.tk.Se.GetSessionVars().StmtCtx.WarningCount(), Equals, uint16(1))
	s.tk.MustQuery("show warnings").Check(testutil.RowsWithSep("|", "Note|1091|column b doesn't exist"))

	// CHANGE COLUMN
	sql = "alter table t1 change column b c int"
	s.tk.MustGetErrCode(sql, mysql.ErrBadField)
	s.mustExec(c, "alter table t1 change column if exists b c int")
	c.Assert(s.tk.Se.GetSessionVars().StmtCtx.WarningCount(), Equals, uint16(1))
	s.tk.MustQuery("show warnings").Check(testutil.RowsWithSep("|", "Note|1054|Unknown column 'b' in 't1'"))
	s.mustExec(c, "alter table t1 change column if exists a c int") // only `c` exists now

	// MODIFY COLUMN
	sql = "alter table t1 modify column a bigint"
	s.tk.MustGetErrCode(sql, mysql.ErrBadField)
	s.mustExec(c, "alter table t1 modify column if exists a bigint")
	c.Assert(s.tk.Se.GetSessionVars().StmtCtx.WarningCount(), Equals, uint16(1))
	s.tk.MustQuery("show warnings").Check(testutil.RowsWithSep("|", "Note|1054|Unknown column 'a' in 't1'"))
	s.mustExec(c, "alter table t1 modify column if exists c bigint") // only `c` exists now

	// DROP INDEX
	s.mustExec(c, "alter table t1 add index idx_c (c)")
	sql = "alter table t1 drop index idx_c"
	s.mustExec(c, sql)
	s.tk.MustGetErrCode(sql, mysql.ErrCantDropFieldOrKey)
	s.mustExec(c, "alter table t1 drop index if exists idx_c")
	c.Assert(s.tk.Se.GetSessionVars().StmtCtx.WarningCount(), Equals, uint16(1))
	s.tk.MustQuery("show warnings").Check(testutil.RowsWithSep("|", "Note|1091|index idx_c doesn't exist"))

	// DROP PARTITION
	s.mustExec(c, "drop table if exists t2")
	s.mustExec(c, "create table t2 (a int key) partition by range(a) (partition p0 values less than (10), partition p1 values less than (20))")
	sql = "alter table t2 drop partition p1"
	s.mustExec(c, sql)
	s.tk.MustGetErrCode(sql, mysql.ErrDropPartitionNonExistent)
	s.mustExec(c, "alter table t2 drop partition if exists p1")
	c.Assert(s.tk.Se.GetSessionVars().StmtCtx.WarningCount(), Equals, uint16(1))
	s.tk.MustQuery("show warnings").Check(testutil.RowsWithSep("|", "Note|1507|Error in list of partitions to p1"))
}

func (s *testDBSuite5) TestAddIndexForGeneratedColumn(c *C) {
	s.tk = testkit.NewTestKit(c, s.store)
	s.tk.MustExec("use test_db")
	s.tk.MustExec("create table t(y year NOT NULL DEFAULT '2155')")
	defer s.mustExec(c, "drop table t;")
	for i := 0; i < 50; i++ {
		s.mustExec(c, "insert into t values (?)", i)
	}
	s.tk.MustExec("insert into t values()")
	s.tk.MustExec("ALTER TABLE t ADD COLUMN y1 year as (y + 2)")
	_, err := s.tk.Exec("ALTER TABLE t ADD INDEX idx_y(y1)")
	c.Assert(err.Error(), Equals, "[ddl:8202]Cannot decode index value, because cannot convert datum from unsigned bigint to type year.")

	t := s.testGetTable(c, "t")
	for _, idx := range t.Indices() {
		c.Assert(strings.EqualFold(idx.Meta().Name.L, "idx_c2"), IsFalse)
	}
	// NOTE: this test case contains a bug, it should be uncommented after the bug is fixed.
	// TODO: Fix bug https://github.com/pingcap/tidb/issues/12181
	//s.mustExec(c, "delete from t where y = 2155")
	//s.mustExec(c, "alter table t add index idx_y(y1)")
	//s.mustExec(c, "alter table t drop index idx_y")

	// Fix issue 9311.
	s.tk.MustExec("create table gcai_table (id int primary key);")
	s.tk.MustExec("insert into gcai_table values(1);")
	s.tk.MustExec("ALTER TABLE gcai_table ADD COLUMN d date DEFAULT '9999-12-31';")
	s.tk.MustExec("ALTER TABLE gcai_table ADD COLUMN d1 date as (DATE_SUB(d, INTERVAL 31 DAY));")
	s.tk.MustExec("ALTER TABLE gcai_table ADD INDEX idx(d1);")
	s.tk.MustQuery("select * from gcai_table").Check(testkit.Rows("1 9999-12-31 9999-11-30"))
	s.tk.MustQuery("select d1 from gcai_table use index(idx)").Check(testkit.Rows("9999-11-30"))
	s.tk.MustExec("admin check table gcai_table")
	// The column is PKIsHandle in generated column expression.
	s.tk.MustExec("ALTER TABLE gcai_table ADD COLUMN id1 int as (id+5);")
	s.tk.MustExec("ALTER TABLE gcai_table ADD INDEX idx1(id1);")
	s.tk.MustQuery("select * from gcai_table").Check(testkit.Rows("1 9999-12-31 9999-11-30 6"))
	s.tk.MustQuery("select id1 from gcai_table use index(idx1)").Check(testkit.Rows("6"))
	s.tk.MustExec("admin check table gcai_table")
}

func (s *testDBSuite5) TestModifyGeneratedColumn(c *C) {
	tk := testkit.NewTestKit(c, s.store)
	tk.MustExec("create database if not exists test;")
	tk.MustExec("use test")
	modIdxColErrMsg := "[ddl:3106]'modifying an indexed column' is not supported for generated columns."
	modStoredColErrMsg := "[ddl:3106]'modifying a stored column' is not supported for generated columns."

	// Modify column with single-col-index.
	tk.MustExec("drop table if exists t1;")
	tk.MustExec("create table t1 (a int, b int as (a+1), index idx(b));")
	tk.MustExec("insert into t1 set a=1;")
	_, err := tk.Exec("alter table t1 modify column b int as (a+2);")
	c.Assert(err, NotNil)
	c.Assert(err.Error(), Equals, modIdxColErrMsg)
	tk.MustExec("drop index idx on t1;")
	tk.MustExec("alter table t1 modify b int as (a+2);")
	tk.MustQuery("select * from t1").Check(testkit.Rows("1 3"))

	// Modify column with multi-col-index.
	tk.MustExec("drop table t1;")
	tk.MustExec("create table t1 (a int, b int as (a+1), index idx(a, b));")
	tk.MustExec("insert into t1 set a=1;")
	_, err = tk.Exec("alter table t1 modify column b int as (a+2);")
	c.Assert(err, NotNil)
	c.Assert(err.Error(), Equals, modIdxColErrMsg)
	tk.MustExec("drop index idx on t1;")
	tk.MustExec("alter table t1 modify b int as (a+2);")
	tk.MustQuery("select * from t1").Check(testkit.Rows("1 3"))

	// Modify column with stored status to a different expression.
	tk.MustExec("drop table t1;")
	tk.MustExec("create table t1 (a int, b int as (a+1) stored);")
	tk.MustExec("insert into t1 set a=1;")
	_, err = tk.Exec("alter table t1 modify column b int as (a+2) stored;")
	c.Assert(err, NotNil)
	c.Assert(err.Error(), Equals, modStoredColErrMsg)

	// Modify column with stored status to the same expression.
	tk.MustExec("drop table t1;")
	tk.MustExec("create table t1 (a int, b int as (a+1) stored);")
	tk.MustExec("insert into t1 set a=1;")
	tk.MustExec("alter table t1 modify column b bigint as (a+1) stored;")
	tk.MustExec("alter table t1 modify column b bigint as (a + 1) stored;")
	tk.MustQuery("select * from t1").Check(testkit.Rows("1 2"))

	// Modify column with index to the same expression.
	tk.MustExec("drop table t1;")
	tk.MustExec("create table t1 (a int, b int as (a+1), index idx(b));")
	tk.MustExec("insert into t1 set a=1;")
	tk.MustExec("alter table t1 modify column b bigint as (a+1);")
	tk.MustExec("alter table t1 modify column b bigint as (a + 1);")
	tk.MustQuery("select * from t1").Check(testkit.Rows("1 2"))

	// Modify column from non-generated to stored generated.
	tk.MustExec("drop table t1;")
	tk.MustExec("create table t1 (a int, b int);")
	_, err = tk.Exec("alter table t1 modify column b bigint as (a+1) stored;")
	c.Assert(err, NotNil)
	c.Assert(err.Error(), Equals, modStoredColErrMsg)

	// Modify column from stored generated to non-generated.
	tk.MustExec("drop table t1;")
	tk.MustExec("create table t1 (a int, b int as (a+1) stored);")
	tk.MustExec("insert into t1 set a=1;")
	tk.MustExec("alter table t1 modify column b int;")
	tk.MustQuery("select * from t1").Check(testkit.Rows("1 2"))
}

func (s *testDBSuite5) TestDefaultSQLFunction(c *C) {
	tk := testkit.NewTestKit(c, s.store)
	tk.MustExec("create database if not exists test;")
	tk.MustExec("use test;")
	tk.MustExec("drop table if exists t1, t2, t3, t4;")

	// For issue #13189
	// Use `DEFAULT()` in `INSERT` / `INSERT ON DUPLICATE KEY UPDATE` statement
	tk.MustExec("create table t1(a int primary key, b int default 20, c int default 30, d int default 40);")
	tk.MustExec("insert into t1 set a = 1, b = default(c);")
	tk.MustQuery("select * from t1;").Check(testkit.Rows("1 30 30 40"))
	tk.MustExec("insert into t1 set a = 2, b = default(c), c = default(d), d = default(b);")
	tk.MustQuery("select * from t1;").Check(testkit.Rows("1 30 30 40", "2 30 40 20"))
	tk.MustExec("insert into t1 values (2, 3, 4, 5) on duplicate key update b = default(d), c = default(b);")
	tk.MustQuery("select * from t1;").Check(testkit.Rows("1 30 30 40", "2 40 20 20"))
	tk.MustExec("delete from t1")
	tk.MustExec("insert into t1 set a = default(b) + default(c) - default(d)")
	tk.MustQuery("select * from t1;").Check(testkit.Rows("10 20 30 40"))
	// Use `DEFAULT()` in `UPDATE` statement
	tk.MustExec("delete from t1;")
	tk.MustExec("insert into t1 value (1, 2, 3, 4);")
	tk.MustExec("update t1 set a = 1, c = default(b);")
	tk.MustQuery("select * from t1;").Check(testkit.Rows("1 2 20 4"))
	tk.MustExec("insert into t1 value (2, 2, 3, 4);")
	tk.MustExec("update t1 set c = default(b), b = default(c) where a = 2;")
	tk.MustQuery("select * from t1;").Check(testkit.Rows("1 2 20 4", "2 30 20 4"))
	tk.MustExec("delete from t1")
	tk.MustExec("insert into t1 set a = 10")
	tk.MustExec("update t1 set a = 10, b = default(c) + default(d)")
	tk.MustQuery("select * from t1;").Check(testkit.Rows("10 70 30 40"))
	// Use `DEFAULT()` in `REPLACE` statement
	tk.MustExec("delete from t1;")
	tk.MustExec("insert into t1 value (1, 2, 3, 4);")
	tk.MustExec("replace into t1 set a = 1, c = default(b);")
	tk.MustQuery("select * from t1;").Check(testkit.Rows("1 20 20 40"))
	tk.MustExec("insert into t1 value (2, 2, 3, 4);")
	tk.MustExec("replace into t1 set a = 2, d = default(b), c = default(d);")
	tk.MustQuery("select * from t1;").Check(testkit.Rows("1 20 20 40", "2 20 40 20"))
	tk.MustExec("delete from t1")
	tk.MustExec("insert into t1 set a = 10, c = 3")
	tk.MustExec("replace into t1 set a = 10, b = default(c) + default(d)")
	tk.MustQuery("select * from t1;").Check(testkit.Rows("10 70 30 40"))
	tk.MustExec("replace into t1 set a = 20, d = default(c) + default(b)")
	tk.MustQuery("select * from t1;").Check(testkit.Rows("10 70 30 40", "20 20 30 50"))

	// Use `DEFAULT()` in expression of generate columns, issue #12471
	tk.MustExec("create table t2(a int default 9, b int as (1 + default(a)));")
	tk.MustExec("insert into t2 values(1, default);")
	tk.MustQuery("select * from t2;").Check(testkit.Rows("1 10"))

	// Use `DEFAULT()` with subquery, issue #13390
	tk.MustExec("create table t3(f1 int default 11);")
	tk.MustExec("insert into t3 value ();")
	tk.MustQuery("select default(f1) from (select * from t3) t1;").Check(testkit.Rows("11"))
	tk.MustQuery("select default(f1) from (select * from (select * from t3) t1 ) t1;").Check(testkit.Rows("11"))

	tk.MustExec("create table t4(a int default 4);")
	tk.MustExec("insert into t4 value (2);")
	tk.MustQuery("select default(c) from (select b as c from (select a as b from t4) t3) t2;").Check(testkit.Rows("4"))
	tk.MustGetErrCode("select default(a) from (select a from (select 1 as a) t4) t4;", mysql.ErrNoDefaultForField)

	tk.MustExec("drop table t1, t2, t3, t4;")
}

func (s *testDBSuite4) TestIssue9100(c *C) {
	tk := testkit.NewTestKit(c, s.store)
	tk.MustExec("use test_db")
	tk.MustExec("create table employ (a int, b int) partition by range (b) (partition p0 values less than (1));")
	_, err := tk.Exec("alter table employ add unique index p_a (a);")
	c.Assert(err.Error(), Equals, "[ddl:1503]A UNIQUE INDEX must include all columns in the table's partitioning function")
	_, err = tk.Exec("alter table employ add primary key p_a (a);")
	c.Assert(err.Error(), Equals, "[ddl:1503]A PRIMARY must include all columns in the table's partitioning function")

	tk.MustExec("create table issue9100t1 (col1 int not null, col2 date not null, col3 int not null, unique key (col1, col2)) partition by range( col1 ) (partition p1 values less than (11))")
	tk.MustExec("alter table issue9100t1 add unique index p_col1 (col1)")
	tk.MustExec("alter table issue9100t1 add primary key p_col1 (col1)")

	tk.MustExec("create table issue9100t2 (col1 int not null, col2 date not null, col3 int not null, unique key (col1, col3)) partition by range( col1 + col3 ) (partition p1 values less than (11))")
	_, err = tk.Exec("alter table issue9100t2 add unique index p_col1 (col1)")
	c.Assert(err.Error(), Equals, "[ddl:1503]A UNIQUE INDEX must include all columns in the table's partitioning function")
	_, err = tk.Exec("alter table issue9100t2 add primary key p_col1 (col1)")
	c.Assert(err.Error(), Equals, "[ddl:1503]A PRIMARY must include all columns in the table's partitioning function")
}

func (s *testDBSuite1) TestModifyColumnCharset(c *C) {
	s.tk = testkit.NewTestKit(c, s.store)
	s.tk.MustExec("use test_db")
	s.tk.MustExec("create table t_mcc(a varchar(8) charset utf8, b varchar(8) charset utf8)")
	defer s.mustExec(c, "drop table t_mcc;")

	result := s.tk.MustQuery(`show create table t_mcc`)
	result.Check(testkit.Rows(
		"t_mcc CREATE TABLE `t_mcc` (\n" +
			"  `a` varchar(8) CHARACTER SET utf8 COLLATE utf8_bin DEFAULT NULL,\n" +
			"  `b` varchar(8) CHARACTER SET utf8 COLLATE utf8_bin DEFAULT NULL\n" +
			") ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin"))

	s.tk.MustExec("alter table t_mcc modify column a varchar(8);")
	t := s.testGetTable(c, "t_mcc")
	t.Meta().Version = model.TableInfoVersion0
	// When the table version is TableInfoVersion0, the following statement don't change "b" charset.
	// So the behavior is not compatible with MySQL.
	s.tk.MustExec("alter table t_mcc modify column b varchar(8);")
	result = s.tk.MustQuery(`show create table t_mcc`)
	result.Check(testkit.Rows(
		"t_mcc CREATE TABLE `t_mcc` (\n" +
			"  `a` varchar(8) DEFAULT NULL,\n" +
			"  `b` varchar(8) CHARACTER SET utf8 COLLATE utf8_bin DEFAULT NULL\n" +
			") ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin"))

}

func (s *testDBSuite1) TestSetTableFlashReplica(c *C) {
	s.tk = testkit.NewTestKit(c, s.store)
	s.tk.MustExec("use test_db")
	s.mustExec(c, "drop table if exists t_flash;")
	s.tk.MustExec("create table t_flash(a int, b int)")
	defer s.mustExec(c, "drop table t_flash;")

	t := s.testGetTable(c, "t_flash")
	c.Assert(t.Meta().TiFlashReplica, IsNil)

	s.tk.MustExec("alter table t_flash set tiflash replica 2 location labels 'a','b';")
	t = s.testGetTable(c, "t_flash")
	c.Assert(t.Meta().TiFlashReplica, NotNil)
	c.Assert(t.Meta().TiFlashReplica.Count, Equals, uint64(2))
	c.Assert(strings.Join(t.Meta().TiFlashReplica.LocationLabels, ","), Equals, strings.Join([]string{"a", "b"}, ","))

	s.tk.MustExec("alter table t_flash set tiflash replica 0")
	t = s.testGetTable(c, "t_flash")
	c.Assert(t.Meta().TiFlashReplica, IsNil)
}

func (s *testDBSuite4) TestAlterShardRowIDBits(c *C) {
	c.Assert(failpoint.Enable("github.com/pingcap/tidb/meta/autoid/mockAutoIDChange", `return(true)`), IsNil)
	defer func() {
		c.Assert(failpoint.Disable("github.com/pingcap/tidb/meta/autoid/mockAutoIDChange"), IsNil)
	}()

	s.tk = testkit.NewTestKit(c, s.store)
	tk := s.tk

	tk.MustExec("use test")
	// Test alter shard_row_id_bits
	tk.MustExec("drop table if exists t1")
	defer tk.MustExec("drop table if exists t1")
	tk.MustExec("create table t1 (a int) shard_row_id_bits = 5")
	tk.MustExec(fmt.Sprintf("alter table t1 auto_increment = %d;", 1<<56))
	tk.MustExec("insert into t1 set a=1;")

	// Test increase shard_row_id_bits failed by overflow global auto ID.
	_, err := tk.Exec("alter table t1 SHARD_ROW_ID_BITS = 10;")
	c.Assert(err, NotNil)
	c.Assert(err.Error(), Equals, "[autoid:1467]shard_row_id_bits 10 will cause next global auto ID 72057594037932936 overflow")

	// Test reduce shard_row_id_bits will be ok.
	tk.MustExec("alter table t1 SHARD_ROW_ID_BITS = 3;")
	checkShardRowID := func(maxShardRowIDBits, shardRowIDBits uint64) {
		tbl := testGetTableByName(c, tk.Se, "test", "t1")
		c.Assert(tbl.Meta().MaxShardRowIDBits == maxShardRowIDBits, IsTrue)
		c.Assert(tbl.Meta().ShardRowIDBits == shardRowIDBits, IsTrue)
	}
	checkShardRowID(5, 3)

	// Test reduce shard_row_id_bits but calculate overflow should use the max record shard_row_id_bits.
	tk.MustExec("drop table if exists t1")
	tk.MustExec("create table t1 (a int) shard_row_id_bits = 10")
	tk.MustExec("alter table t1 SHARD_ROW_ID_BITS = 5;")
	checkShardRowID(10, 5)
	tk.MustExec(fmt.Sprintf("alter table t1 auto_increment = %d;", 1<<56))
	_, err = tk.Exec("insert into t1 set a=1;")
	c.Assert(err, NotNil)
	c.Assert(err.Error(), Equals, "[autoid:1467]Failed to read auto-increment value from storage engine")
}

// port from mysql
// https://github.com/mysql/mysql-server/blob/124c7ab1d6f914637521fd4463a993aa73403513/mysql-test/t/lock.test
func (s *testDBSuite2) TestLock(c *C) {
	s.tk = testkit.NewTestKit(c, s.store)
	tk := s.tk
	tk.MustExec("use test")

	/* Testing of table locking */
	tk.MustExec("DROP TABLE IF EXISTS t1")
	tk.MustExec("CREATE TABLE t1 (  `id` int(11) NOT NULL default '0', `id2` int(11) NOT NULL default '0', `id3` int(11) NOT NULL default '0', `dummy1` char(30) default NULL, PRIMARY KEY  (`id`,`id2`), KEY `index_id3` (`id3`))")
	tk.MustExec("insert into t1 (id,id2) values (1,1),(1,2),(1,3)")
	tk.MustExec("LOCK TABLE t1 WRITE")
	tk.MustExec("select dummy1,count(distinct id) from t1 group by dummy1")
	tk.MustExec("update t1 set id=-1 where id=1")
	tk.MustExec("LOCK TABLE t1 READ")
	_, err := tk.Exec("update t1 set id=1 where id=1")
	c.Assert(terror.ErrorEqual(err, infoschema.ErrTableNotLockedForWrite), IsTrue)
	tk.MustExec("unlock tables")
	tk.MustExec("update t1 set id=1 where id=-1")
	tk.MustExec("drop table t1")
}

// port from mysql
// https://github.com/mysql/mysql-server/blob/4f1d7cf5fcb11a3f84cff27e37100d7295e7d5ca/mysql-test/t/tablelock.test
func (s *testDBSuite2) TestTableLock(c *C) {
	s.tk = testkit.NewTestKit(c, s.store)
	tk := s.tk
	tk.MustExec("use test")
	tk.MustExec("drop table if exists t1,t2")

	/* Test of lock tables */
	tk.MustExec("create table t1 ( n int auto_increment primary key)")
	tk.MustExec("lock tables t1 write")
	tk.MustExec("insert into t1 values(NULL)")
	tk.MustExec("unlock tables")
	checkTableLock(c, tk.Se, "test", "t1", model.TableLockNone)

	tk.MustExec("lock tables t1 write")
	tk.MustExec("insert into t1 values(NULL)")
	tk.MustExec("unlock tables")
	checkTableLock(c, tk.Se, "test", "t1", model.TableLockNone)

	tk.MustExec("drop table if exists t1")

	/* Test of locking and delete of files */
	tk.MustExec("drop table if exists t1,t2")
	tk.MustExec("CREATE TABLE t1 (a int)")
	tk.MustExec("CREATE TABLE t2 (a int)")
	tk.MustExec("lock tables t1 write, t2 write")
	tk.MustExec("drop table t1,t2")

	tk.MustExec("CREATE TABLE t1 (a int)")
	tk.MustExec("CREATE TABLE t2 (a int)")
	tk.MustExec("lock tables t1 write, t2 write")
	tk.MustExec("drop table t2,t1")
}

// port from mysql
// https://github.com/mysql/mysql-server/blob/4f1d7cf5fcb11a3f84cff27e37100d7295e7d5ca/mysql-test/t/lock_tables_lost_commit.test
func (s *testDBSuite2) TestTableLocksLostCommit(c *C) {
	s.tk = testkit.NewTestKit(c, s.store)
	tk2 := testkit.NewTestKit(c, s.store)
	tk := s.tk
	tk.MustExec("use test")
	tk2.MustExec("use test")

	tk.MustExec("DROP TABLE IF EXISTS t1")
	tk.MustExec("CREATE TABLE t1(a INT)")
	tk.MustExec("LOCK TABLES t1 WRITE")
	tk.MustExec("INSERT INTO t1 VALUES(10)")

	_, err := tk2.Exec("SELECT * FROM t1")
	c.Assert(terror.ErrorEqual(err, infoschema.ErrTableLocked), IsTrue)

	tk.Se.Close()

	tk2.MustExec("SELECT * FROM t1")
	tk2.MustExec("DROP TABLE t1")

	tk.MustExec("unlock tables")
}

// test write local lock
func (s *testDBSuite2) TestWriteLocal(c *C) {
	s.tk = testkit.NewTestKit(c, s.store)
	tk2 := testkit.NewTestKit(c, s.store)
	tk := s.tk
	tk.MustExec("use test")
	tk2.MustExec("use test")
	tk.MustExec("drop table if exists t1")
	tk.MustExec("create table t1 ( n int auto_increment primary key)")

	// Test: allow read
	tk.MustExec("lock tables t1 write local")
	tk.MustExec("insert into t1 values(NULL)")
	tk2.MustQuery("select count(*) from t1")
	tk.MustExec("unlock tables")
	tk2.MustExec("unlock tables")

	// Test: forbid write
	tk.MustExec("lock tables t1 write local")
	_, err := tk2.Exec("insert into t1 values(NULL)")
	c.Assert(terror.ErrorEqual(err, infoschema.ErrTableLocked), IsTrue)
	tk.MustExec("unlock tables")
	tk2.MustExec("unlock tables")

	// Test mutex: lock write local first
	tk.MustExec("lock tables t1 write local")
	_, err = tk2.Exec("lock tables t1 write local")
	c.Assert(terror.ErrorEqual(err, infoschema.ErrTableLocked), IsTrue)
	_, err = tk2.Exec("lock tables t1 write")
	c.Assert(terror.ErrorEqual(err, infoschema.ErrTableLocked), IsTrue)
	_, err = tk2.Exec("lock tables t1 read")
	c.Assert(terror.ErrorEqual(err, infoschema.ErrTableLocked), IsTrue)
	tk.MustExec("unlock tables")
	tk2.MustExec("unlock tables")

	// Test mutex: lock write first
	tk.MustExec("lock tables t1 write")
	_, err = tk2.Exec("lock tables t1 write local")
	c.Assert(terror.ErrorEqual(err, infoschema.ErrTableLocked), IsTrue)
	tk.MustExec("unlock tables")
	tk2.MustExec("unlock tables")

	// Test mutex: lock read first
	tk.MustExec("lock tables t1 read")
	_, err = tk2.Exec("lock tables t1 write local")
	c.Assert(terror.ErrorEqual(err, infoschema.ErrTableLocked), IsTrue)
	tk.MustExec("unlock tables")
	tk2.MustExec("unlock tables")
}

func (s *testDBSuite2) TestSkipSchemaChecker(c *C) {
	s.tk = testkit.NewTestKit(c, s.store)
	tk := s.tk
	tk.MustExec("use test")
	tk.MustExec("drop table if exists t1")
	defer tk.MustExec("drop table if exists t1")
	tk.MustExec("create table t1 (a int)")
	tk2 := testkit.NewTestKit(c, s.store)
	tk2.MustExec("use test")

	// Test skip schema checker for ActionSetTiFlashReplica.
	tk.MustExec("begin")
	tk.MustExec("insert into t1 set a=1;")
	tk2.MustExec("alter table t1 set tiflash replica 2 location labels 'a','b';")
	tk.MustExec("commit")

	// Test skip schema checker for ActionUpdateTiFlashReplicaStatus.
	tk.MustExec("begin")
	tk.MustExec("insert into t1 set a=1;")
	tb := testGetTableByName(c, s.tk.Se, "test", "t1")
	err := domain.GetDomain(s.tk.Se).DDL().UpdateTableReplicaInfo(s.tk.Se, tb.Meta().ID, true)
	c.Assert(err, IsNil)
	tk.MustExec("commit")

	// Test can't skip schema checker.
	tk.MustExec("begin")
	tk.MustExec("insert into t1 set a=1;")
	tk2.MustExec("alter table t1 add column b int;")
	_, err = tk.Exec("commit")
	c.Assert(terror.ErrorEqual(domain.ErrInfoSchemaChanged, err), IsTrue)
}

func (s *testDBSuite2) TestLockTables(c *C) {
	if israce.RaceEnabled {
		c.Skip("skip race test")
	}
	s.tk = testkit.NewTestKit(c, s.store)
	tk := s.tk
	tk.MustExec("use test")
	tk.MustExec("drop table if exists t1,t2")
	defer tk.MustExec("drop table if exists t1,t2")
	tk.MustExec("create table t1 (a int)")
	tk.MustExec("create table t2 (a int)")

	// Test lock 1 table.
	tk.MustExec("lock tables t1 write")
	checkTableLock(c, tk.Se, "test", "t1", model.TableLockWrite)
	tk.MustExec("lock tables t1 read")
	checkTableLock(c, tk.Se, "test", "t1", model.TableLockRead)
	tk.MustExec("lock tables t1 write")
	checkTableLock(c, tk.Se, "test", "t1", model.TableLockWrite)

	// Test lock multi tables.
	tk.MustExec("lock tables t1 write, t2 read")
	checkTableLock(c, tk.Se, "test", "t1", model.TableLockWrite)
	checkTableLock(c, tk.Se, "test", "t2", model.TableLockRead)
	tk.MustExec("lock tables t1 read, t2 write")
	checkTableLock(c, tk.Se, "test", "t1", model.TableLockRead)
	checkTableLock(c, tk.Se, "test", "t2", model.TableLockWrite)
	tk.MustExec("lock tables t2 write")
	checkTableLock(c, tk.Se, "test", "t2", model.TableLockWrite)
	checkTableLock(c, tk.Se, "test", "t1", model.TableLockNone)
	tk.MustExec("lock tables t1 write")
	checkTableLock(c, tk.Se, "test", "t1", model.TableLockWrite)
	checkTableLock(c, tk.Se, "test", "t2", model.TableLockNone)

	tk2 := testkit.NewTestKit(c, s.store)
	tk2.MustExec("use test")

	// Test read lock.
	tk.MustExec("lock tables t1 read")
	tk.MustQuery("select * from t1")
	tk2.MustQuery("select * from t1")
	_, err := tk.Exec("insert into t1 set a=1")
	c.Assert(terror.ErrorEqual(err, infoschema.ErrTableNotLockedForWrite), IsTrue)
	_, err = tk.Exec("update t1 set a=1")
	c.Assert(terror.ErrorEqual(err, infoschema.ErrTableNotLockedForWrite), IsTrue)
	_, err = tk.Exec("delete from t1")
	c.Assert(terror.ErrorEqual(err, infoschema.ErrTableNotLockedForWrite), IsTrue)

	_, err = tk2.Exec("insert into t1 set a=1")
	c.Assert(terror.ErrorEqual(err, infoschema.ErrTableLocked), IsTrue)
	_, err = tk2.Exec("update t1 set a=1")
	c.Assert(terror.ErrorEqual(err, infoschema.ErrTableLocked), IsTrue)
	_, err = tk2.Exec("delete from t1")
	c.Assert(terror.ErrorEqual(err, infoschema.ErrTableLocked), IsTrue)
	tk2.MustExec("lock tables t1 read")
	_, err = tk2.Exec("insert into t1 set a=1")
	c.Assert(terror.ErrorEqual(err, infoschema.ErrTableNotLockedForWrite), IsTrue)

	// Test write lock.
	_, err = tk.Exec("lock tables t1 write")
	c.Assert(terror.ErrorEqual(err, infoschema.ErrTableLocked), IsTrue)
	tk2.MustExec("unlock tables")
	tk.MustExec("lock tables t1 write")
	tk.MustQuery("select * from t1")
	tk.MustExec("delete from t1")
	tk.MustExec("insert into t1 set a=1")

	_, err = tk2.Exec("select * from t1")
	c.Assert(terror.ErrorEqual(err, infoschema.ErrTableLocked), IsTrue)
	_, err = tk2.Exec("insert into t1 set a=1")
	c.Assert(terror.ErrorEqual(err, infoschema.ErrTableLocked), IsTrue)
	_, err = tk2.Exec("lock tables t1 write")
	c.Assert(terror.ErrorEqual(err, infoschema.ErrTableLocked), IsTrue)

	// Test write local lock.
	tk.MustExec("lock tables t1 write local")
	tk.MustQuery("select * from t1")
	tk.MustExec("delete from t1")
	tk.MustExec("insert into t1 set a=1")

	tk2.MustQuery("select * from t1")
	_, err = tk2.Exec("delete from t1")
	c.Assert(terror.ErrorEqual(err, infoschema.ErrTableLocked), IsTrue)
	_, err = tk2.Exec("insert into t1 set a=1")
	c.Assert(terror.ErrorEqual(err, infoschema.ErrTableLocked), IsTrue)
	_, err = tk2.Exec("lock tables t1 write")
	c.Assert(terror.ErrorEqual(err, infoschema.ErrTableLocked), IsTrue)
	_, err = tk2.Exec("lock tables t1 read")
	c.Assert(terror.ErrorEqual(err, infoschema.ErrTableLocked), IsTrue)

	// Test none unique table.
	_, err = tk.Exec("lock tables t1 read, t1 write")
	c.Assert(terror.ErrorEqual(err, infoschema.ErrNonuniqTable), IsTrue)

	// Test lock table by other session in transaction and commit without retry.
	tk.MustExec("unlock tables")
	tk2.MustExec("unlock tables")
	tk.MustExec("set @@session.tidb_disable_txn_auto_retry=1")
	tk.MustExec("begin")
	tk.MustExec("insert into t1 set a=1")
	tk2.MustExec("lock tables t1 write")
	_, err = tk.Exec("commit")
	c.Assert(err, NotNil)
	c.Assert(err.Error(), Equals, "previous statement: insert into t1 set a=1: [domain:8028]Information schema is changed during the execution of the statement(for example, table definition may be updated by other DDL ran in parallel). If you see this error often, try increasing `tidb_max_delta_schema_count`. [try again later]")

	// Test lock table by other session in transaction and commit with retry.
	tk.MustExec("unlock tables")
	tk2.MustExec("unlock tables")
	tk.MustExec("set @@session.tidb_disable_txn_auto_retry=0")
	tk.MustExec("begin")
	tk.MustExec("insert into t1 set a=1")
	tk2.MustExec("lock tables t1 write")
	_, err = tk.Exec("commit")
	c.Assert(terror.ErrorEqual(err, infoschema.ErrTableLocked), IsTrue, Commentf("err: %v\n", err))

	// Test for lock the same table multiple times.
	tk2.MustExec("lock tables t1 write")
	tk2.MustExec("lock tables t1 write, t2 read")

	// Test lock tables and drop tables
	tk.MustExec("unlock tables")
	tk2.MustExec("unlock tables")
	tk.MustExec("lock tables t1 write, t2 write")
	tk.MustExec("drop table t1")
	tk2.MustExec("create table t1 (a int)")
	tk.MustExec("lock tables t1 write, t2 read")

	// Test lock tables and drop database.
	tk.MustExec("unlock tables")
	tk.MustExec("create database test_lock")
	tk.MustExec("create table test_lock.t3 (a int)")
	tk.MustExec("lock tables t1 write, test_lock.t3 write")
	tk2.MustExec("create table t3 (a int)")
	tk.MustExec("lock tables t1 write, t3 write")
	tk.MustExec("drop table t3")

	// Test lock tables and truncate tables.
	tk.MustExec("unlock tables")
	tk.MustExec("lock tables t1 write, t2 read")
	tk.MustExec("truncate table t1")
	tk.MustExec("insert into t1 set a=1")
	_, err = tk2.Exec("insert into t1 set a=1")
	c.Assert(terror.ErrorEqual(err, infoschema.ErrTableLocked), IsTrue)

	// Test for lock unsupported schema tables.
	_, err = tk2.Exec("lock tables performance_schema.global_status write")
	c.Assert(terror.ErrorEqual(err, infoschema.ErrAccessDenied), IsTrue)
	_, err = tk2.Exec("lock tables information_schema.tables write")
	c.Assert(terror.ErrorEqual(err, infoschema.ErrAccessDenied), IsTrue)
	_, err = tk2.Exec("lock tables mysql.db write")
	c.Assert(terror.ErrorEqual(err, infoschema.ErrAccessDenied), IsTrue)

	// Test create table/view when session is holding the table locks.
	tk.MustExec("unlock tables")
	tk.MustExec("lock tables t1 write, t2 read")
	_, err = tk.Exec("create table t3 (a int)")
	c.Assert(terror.ErrorEqual(err, infoschema.ErrTableNotLocked), IsTrue)
	_, err = tk.Exec("create view v1 as select * from t1;")
	c.Assert(terror.ErrorEqual(err, infoschema.ErrTableNotLocked), IsTrue)

	// Test for lock view was not supported.
	tk.MustExec("unlock tables")
	tk.MustExec("create view v1 as select * from t1;")
	_, err = tk.Exec("lock tables v1 read")
	c.Assert(terror.ErrorEqual(err, table.ErrUnsupportedOp), IsTrue)

	// Test for create/drop/alter database when session is holding the table locks.
	tk.MustExec("unlock tables")
	tk.MustExec("lock table t1 write")
	_, err = tk.Exec("drop database test")
	c.Assert(terror.ErrorEqual(err, table.ErrLockOrActiveTransaction), IsTrue)
	_, err = tk.Exec("create database test_lock")
	c.Assert(terror.ErrorEqual(err, table.ErrLockOrActiveTransaction), IsTrue)
	_, err = tk.Exec("alter database test charset='utf8mb4'")
	c.Assert(terror.ErrorEqual(err, table.ErrLockOrActiveTransaction), IsTrue)
	// Test alter/drop database when other session is holding the table locks of the database.
	tk2.MustExec("create database test_lock2")
	_, err = tk2.Exec("drop database test")
	c.Assert(terror.ErrorEqual(err, infoschema.ErrTableLocked), IsTrue)
	_, err = tk2.Exec("alter database test charset='utf8mb4'")
	c.Assert(terror.ErrorEqual(err, infoschema.ErrTableLocked), IsTrue)

	// Test for admin cleanup table locks.
	tk.MustExec("unlock tables")
	tk.MustExec("lock table t1 write, t2 write")
	_, err = tk2.Exec("lock tables t1 write, t2 read")
	c.Assert(terror.ErrorEqual(err, infoschema.ErrTableLocked), IsTrue)
	tk2.MustExec("admin cleanup table lock t1,t2")
	checkTableLock(c, tk.Se, "test", "t1", model.TableLockNone)
	checkTableLock(c, tk.Se, "test", "t2", model.TableLockNone)
	// cleanup unlocked table.
	tk2.MustExec("admin cleanup table lock t1,t2")
	checkTableLock(c, tk.Se, "test", "t1", model.TableLockNone)
	checkTableLock(c, tk.Se, "test", "t2", model.TableLockNone)
	tk2.MustExec("lock tables t1 write, t2 read")
	checkTableLock(c, tk2.Se, "test", "t1", model.TableLockWrite)
	checkTableLock(c, tk2.Se, "test", "t2", model.TableLockRead)

	tk.MustExec("unlock tables")
	tk2.MustExec("unlock tables")
}

func (s *testDBSuite2) TestTablesLockDelayClean(c *C) {
	if israce.RaceEnabled {
		c.Skip("skip race test")
	}
	s.tk = testkit.NewTestKit(c, s.store)
	tk := s.tk
	tk2 := testkit.NewTestKit(c, s.store)
	tk2.MustExec("use test")
	tk.MustExec("use test")
	tk.MustExec("drop table if exists t1,t2")
	defer tk.MustExec("drop table if exists t1,t2")
	tk.MustExec("create table t1 (a int)")
	tk.MustExec("create table t2 (a int)")

	tk.MustExec("lock tables t1 write")
	checkTableLock(c, tk.Se, "test", "t1", model.TableLockWrite)
	config.GetGlobalConfig().DelayCleanTableLock = 100
	var wg sync.WaitGroup
	wg.Add(1)
	var startTime time.Time
	go func() {
		startTime = time.Now()
		tk.Se.Close()
		wg.Done()
	}()
	time.Sleep(50 * time.Millisecond)
	checkTableLock(c, tk.Se, "test", "t1", model.TableLockWrite)
	wg.Wait()
	c.Assert(time.Since(startTime).Seconds() > 0.1, IsTrue)
	checkTableLock(c, tk.Se, "test", "t1", model.TableLockNone)
	config.GetGlobalConfig().DelayCleanTableLock = 0
}

// TestConcurrentLockTables test concurrent lock/unlock tables.
func (s *testDBSuite4) TestConcurrentLockTables(c *C) {
	if israce.RaceEnabled {
		c.Skip("skip race test")
	}
	s.tk = testkit.NewTestKit(c, s.store)
	tk2 := testkit.NewTestKit(c, s.store)
	tk := s.tk
	tk.MustExec("use test")
	tk.MustExec("drop table if exists t1")
	defer tk.MustExec("drop table if exists t1")
	tk.MustExec("create table t1 (a int)")
	tk2.MustExec("use test")

	// Test concurrent lock tables read.
	sql1 := "lock tables t1 read"
	sql2 := "lock tables t1 read"
	s.testParallelExecSQL(c, sql1, sql2, tk.Se, tk2.Se, func(c *C, err1, err2 error) {
		c.Assert(err1, IsNil)
		c.Assert(err2, IsNil)
	})
	tk.MustExec("unlock tables")
	tk2.MustExec("unlock tables")

	// Test concurrent lock tables write.
	sql1 = "lock tables t1 write"
	sql2 = "lock tables t1 write"
	s.testParallelExecSQL(c, sql1, sql2, tk.Se, tk2.Se, func(c *C, err1, err2 error) {
		c.Assert(err1, IsNil)
		c.Assert(terror.ErrorEqual(err2, infoschema.ErrTableLocked), IsTrue)
	})
	tk.MustExec("unlock tables")
	tk2.MustExec("unlock tables")

	// Test concurrent lock tables write local.
	sql1 = "lock tables t1 write local"
	sql2 = "lock tables t1 write local"
	s.testParallelExecSQL(c, sql1, sql2, tk.Se, tk2.Se, func(c *C, err1, err2 error) {
		c.Assert(err1, IsNil)
		c.Assert(terror.ErrorEqual(err2, infoschema.ErrTableLocked), IsTrue)
	})

	tk.MustExec("unlock tables")
	tk2.MustExec("unlock tables")
}

func (s *testDBSuite4) testParallelExecSQL(c *C, sql1, sql2 string, se1, se2 session.Session, f checkRet) {
	callback := &ddl.TestDDLCallback{}
	times := 0
	callback.OnJobRunBeforeExported = func(job *model.Job) {
		if times != 0 {
			return
		}
		var qLen int
		for {
			err := kv.RunInNewTxn(s.store, false, func(txn kv.Transaction) error {
				jobs, err1 := admin.GetDDLJobs(txn)
				if err1 != nil {
					return err1
				}
				qLen = len(jobs)
				return nil
			})
			c.Assert(err, IsNil)
			if qLen == 2 {
				break
			}
			time.Sleep(5 * time.Millisecond)
		}
		times++
	}
	d := s.dom.DDL()
	originalCallback := d.GetHook()
	defer d.(ddl.DDLForTest).SetHook(originalCallback)
	d.(ddl.DDLForTest).SetHook(callback)

	wg := sync.WaitGroup{}
	var err1 error
	var err2 error
	wg.Add(2)
	ch := make(chan struct{})
	// Make sure the sql1 is put into the DDLJobQueue.
	go func() {
		var qLen int
		for {
			err := kv.RunInNewTxn(s.store, false, func(txn kv.Transaction) error {
				jobs, err3 := admin.GetDDLJobs(txn)
				if err3 != nil {
					return err3
				}
				qLen = len(jobs)
				return nil
			})
			c.Assert(err, IsNil)
			if qLen == 1 {
				// Make sure sql2 is executed after the sql1.
				close(ch)
				break
			}
			time.Sleep(5 * time.Millisecond)
		}
	}()
	go func() {
		defer wg.Done()
		_, err1 = se1.Execute(context.Background(), sql1)
	}()
	go func() {
		defer wg.Done()
		<-ch
		_, err2 = se2.Execute(context.Background(), sql2)
	}()

	wg.Wait()
	f(c, err1, err2)
}

func checkTableLock(c *C, se session.Session, dbName, tableName string, lockTp model.TableLockType) {
	tb := testGetTableByName(c, se, dbName, tableName)
	dom := domain.GetDomain(se)
	if lockTp != model.TableLockNone {
		c.Assert(tb.Meta().Lock, NotNil)
		c.Assert(tb.Meta().Lock.Tp, Equals, lockTp)
		c.Assert(tb.Meta().Lock.State, Equals, model.TableLockStatePublic)
		c.Assert(len(tb.Meta().Lock.Sessions) == 1, IsTrue)
		c.Assert(tb.Meta().Lock.Sessions[0].ServerID, Equals, dom.DDL().GetID())
		c.Assert(tb.Meta().Lock.Sessions[0].SessionID, Equals, se.GetSessionVars().ConnectionID)
	} else {
		c.Assert(tb.Meta().Lock, IsNil)
	}
}

func (s *testDBSuite2) TestDDLWithInvalidTableInfo(c *C) {
	s.tk = testkit.NewTestKit(c, s.store)
	tk := s.tk

	tk.MustExec("use test")
	tk.MustExec("drop table if exists t")
	defer tk.MustExec("drop table if exists t")
	// Test create with invalid expression.
	_, err := s.tk.Exec(`CREATE TABLE t (
		c0 int(11) ,
  		c1 int(11),
    	c2 decimal(16,4) GENERATED ALWAYS AS ((case when (c0 = 0) then 0when (c0 > 0) then (c1 / c0) end))
	);`)
	c.Assert(err, NotNil)
	c.Assert(err.Error(), Equals, "[parser:1064]You have an error in your SQL syntax; check the manual that corresponds to your TiDB version for the right syntax to use line 4 column 88 near \"then (c1 / c0) end))\n\t);\" ")

	tk.MustExec("create table t (a bigint, b int, c int generated always as (b+1)) partition by hash(a) partitions 4;")
	// Test drop partition column.
	_, err = tk.Exec("alter table t drop column a;")
	c.Assert(err, NotNil)
	c.Assert(err.Error(), Equals, "[expression:1054]Unknown column 'a' in 'expression'")
	// Test modify column with invalid expression.
	_, err = tk.Exec("alter table t modify column c int GENERATED ALWAYS AS ((case when (a = 0) then 0when (a > 0) then (b / a) end));")
	c.Assert(err, NotNil)
	c.Assert(err.Error(), Equals, "[parser:1064]You have an error in your SQL syntax; check the manual that corresponds to your TiDB version for the right syntax to use line 1 column 97 near \"then (b / a) end));\" ")
	// Test add column with invalid expression.
	_, err = tk.Exec("alter table t add column d int GENERATED ALWAYS AS ((case when (a = 0) then 0when (a > 0) then (b / a) end));")
	c.Assert(err, NotNil)
	c.Assert(err.Error(), Equals, "[parser:1064]You have an error in your SQL syntax; check the manual that corresponds to your TiDB version for the right syntax to use line 1 column 94 near \"then (b / a) end));\" ")
}

func init() {
	// Make sure it will only be executed once.
	domain.SchemaOutOfDateRetryInterval = int64(50 * time.Millisecond)
}