This is an automated cherry-pick of #51386

Signed-off-by: ti-chi-bot <ti-community-prow-bot@tidb.io>

pkg/ddl/db_integration_test.go

@@ -1172,7 +1172,10 @@ func TestAlterColumn(t *testing.T) {
 	tk.MustExec("alter table test_alter_column alter column d set default null")
 	tk.MustExec("alter table test_alter_column alter column a drop default")
 	tk.MustGetErrCode("insert into test_alter_column set b = 'd', c = 'dd'", errno.ErrNoDefaultForField)
-	tk.MustQuery("select a from test_alter_column").Check(testkit.Rows("111", "222", "222", "123"))
+	tk.MustGetErrCode("insert into test_alter_column set a = DEFAULT, b = 'd', c = 'dd'", errno.ErrNoDefaultForField)
+	tk.MustGetErrCode("insert into test_alter_column values (DEFAULT, 'd', 'dd', DEFAULT)", errno.ErrNoDefaultForField)
+	tk.MustExec("insert into test_alter_column set a = NULL, b = 'd', c = 'dd'")
+	tk.MustQuery("select a from test_alter_column").Check(testkit.Rows("111", "222", "222", "123", "<nil>"))
 
 	// for failing tests
 	sql := "alter table db_not_exist.test_alter_column alter column b set default 'c'"

pkg/executor/insert_common.go

@@ -580,7 +580,14 @@ func (e *InsertValues) getColDefaultValue(idx int, col *table.Column) (d types.D
 	if col.DefaultIsExpr && col.DefaultExpr != nil {
 		defaultVal, err = table.EvalColDefaultExpr(e.Ctx(), col.ToInfo(), col.DefaultExpr)
 	} else {
+<<<<<<< HEAD:pkg/executor/insert_common.go
 		defaultVal, err = table.GetColDefaultValue(e.Ctx(), col.ToInfo())
+=======
+		if err := table.CheckNoDefaultValueForInsert(e.ctx.GetSessionVars().StmtCtx, col.ToInfo()); err != nil {
+			return types.Datum{}, err
+		}
+		defaultVal, err = table.GetColDefaultValue(e.ctx, col.ToInfo())
+>>>>>>> 7b2d727c0e9 (table: fix issue of get default value from column when column doesn't have default value (#51309) (#51386)):executor/insert_common.go
 	}
 	if err != nil {
 		return types.Datum{}, err

pkg/executor/test/executor/executor_test.go

@@ -4308,6 +4308,7 @@ func TestProcessInfoOfSubQuery(t *testing.T) {
 	wg.Wait()
 }
 
+<<<<<<< HEAD:pkg/executor/test/executor/executor_test.go
 func TestIssue38756(t *testing.T) {
 	store := testkit.CreateMockStore(t)
 	tk := testkit.NewTestKit(t, store)
@@ -4351,4 +4352,105 @@ func TestIssues49377(t *testing.T) {
 		"(select * from employee where dept_id = 1 order by employee_id) " +
 		"limit 1" +
 		");").Sort().Check(testkit.Rows("1 Furina 1", "1 Furina 1", "1 Furina 1", "2 Klee 1", "2 Klee 1", "3 Eula 1", "3 Eula 1"))
+=======
+func TestIssue50043(t *testing.T) {
+	store := testkit.CreateMockStore(t)
+	tk := testkit.NewTestKit(t, store)
+	// Test simplified case by update.
+	tk.MustExec("use test")
+	tk.MustExec("create table t (c1 boolean ,c2 decimal ( 37 , 17 ), unique key idx1 (c1 ,c2),unique key idx2 ( c1 ));")
+	tk.MustExec("insert into t values (0,NULL);")
+	tk.MustExec("alter table t alter column c2 drop default;")
+	tk.MustExec("update t set c2 = 5 where c1 = 0;")
+	tk.MustQuery("select * from t order by c1,c2").Check(testkit.Rows("0 5.00000000000000000"))
+
+	// Test simplified case by insert on duplicate key update.
+	tk.MustExec("drop table if exists t")
+	tk.MustExec("create table t (c1 boolean ,c2 decimal ( 37 , 17 ), unique key idx1 (c1 ,c2));")
+	tk.MustExec("alter table t alter column c2 drop default;")
+	tk.MustExec("alter table t add unique key idx4 ( c1 );")
+	tk.MustExec("insert into t values (0, NULL), (1, 1);")
+	tk.MustExec("insert into t values (0, 2) ,(1, 3) on duplicate key update c2 = 5;")
+	tk.MustQuery("show warnings").Check(testkit.Rows())
+	tk.MustQuery("select * from t order by c1,c2").Check(testkit.Rows("0 5.00000000000000000", "1 5.00000000000000000"))
+
+	// Test Issue 50043.
+	tk.MustExec("drop table if exists t")
+	tk.MustExec("create table t (c1 boolean ,c2 decimal ( 37 , 17 ), unique key idx1 (c1 ,c2));")
+	tk.MustExec("alter table t alter column c2 drop default;")
+	tk.MustExec("alter table t add unique key idx4 ( c1 );")
+	tk.MustExec("insert into t values (0, NULL), (1, 1);")
+	tk.MustExec("insert ignore into t values (0, 2) ,(1, 3) on duplicate key update c2 = 5, c1 = 0")
+	tk.MustQuery("select * from t order by c1,c2").Check(testkit.Rows("0 5.00000000000000000", "1 1.00000000000000000"))
+}
+
+func TestIssue51324(t *testing.T) {
+	store := testkit.CreateMockStore(t)
+	tk := testkit.NewTestKit(t, store)
+	tk.MustExec("use test")
+	tk.MustExec("create table t (id int key, a int, b enum('a', 'b'))")
+	tk.MustGetErrMsg("insert into t values ()", "[table:1364]Field 'id' doesn't have a default value")
+	tk.MustExec("insert into t set id = 1")
+	tk.MustExec("insert into t set id = 2, a = NULL, b = NULL")
+	tk.MustExec("insert into t set id = 3, a = DEFAULT, b = DEFAULT")
+	tk.MustQuery("select * from t order by id").Check(testkit.Rows("1 <nil> <nil>", "2 <nil> <nil>", "3 <nil> <nil>"))
+
+	tk.MustExec("alter table t alter column a drop default")
+	tk.MustExec("alter table t alter column b drop default")
+	tk.MustGetErrMsg("insert into t set id = 4;", "[table:1364]Field 'a' doesn't have a default value")
+	tk.MustExec("insert into t set id = 5, a = NULL, b = NULL;")
+	tk.MustGetErrMsg("insert into t set id = 6, a = DEFAULT, b = DEFAULT;", "[table:1364]Field 'a' doesn't have a default value")
+	tk.MustQuery("select * from t order by id").Check(testkit.Rows("1 <nil> <nil>", "2 <nil> <nil>", "3 <nil> <nil>", "5 <nil> <nil>"))
+
+	tk.MustExec("insert ignore into t set id = 4;")
+	tk.MustQuery("show warnings").Check(testkit.Rows("Warning 1364 Field 'a' doesn't have a default value"))
+	tk.MustExec("insert ignore into t set id = 6, a = DEFAULT, b = DEFAULT;")
+	tk.MustQuery("show warnings").Check(testkit.Rows("Warning 1364 Field 'a' doesn't have a default value"))
+	tk.MustQuery("select * from t order by id").Check(testkit.Rows("1 <nil> <nil>", "2 <nil> <nil>", "3 <nil> <nil>", "4 <nil> <nil>", "5 <nil> <nil>", "6 <nil> <nil>"))
+	tk.MustExec("update t set id = id + 10")
+	tk.MustQuery("show warnings").Check(testkit.Rows())
+	tk.MustQuery("select * from t order by id").Check(testkit.Rows("11 <nil> <nil>", "12 <nil> <nil>", "13 <nil> <nil>", "14 <nil> <nil>", "15 <nil> <nil>", "16 <nil> <nil>"))
+
+	// Test not null case.
+	tk.MustExec("drop table t")
+	tk.MustExec("create table t (id int key, a int not null, b enum('a', 'b') not null)")
+	tk.MustGetErrMsg("insert into t values ()", "[table:1364]Field 'id' doesn't have a default value")
+	tk.MustGetErrMsg("insert into t set id = 1", "[table:1364]Field 'a' doesn't have a default value")
+	tk.MustGetErrMsg("insert into t set id = 2, a = NULL, b = NULL", "[table:1048]Column 'a' cannot be null")
+	tk.MustGetErrMsg("insert into t set id = 2, a = 2, b = NULL", "[table:1048]Column 'b' cannot be null")
+	tk.MustGetErrMsg("insert into t set id = 3, a = DEFAULT, b = DEFAULT", "[table:1364]Field 'a' doesn't have a default value")
+	tk.MustExec("alter table t alter column a drop default")
+	tk.MustExec("alter table t alter column b drop default")
+	tk.MustExec("insert ignore into t set id = 4;")
+	tk.MustQuery("show warnings").Check(testkit.Rows("Warning 1364 Field 'a' doesn't have a default value"))
+	tk.MustExec("insert ignore into t set id = 5, a = NULL, b = NULL;")
+	tk.MustQuery("show warnings").Check(testkit.Rows("Warning 1048 Column 'a' cannot be null", "Warning 1048 Column 'b' cannot be null"))
+	tk.MustExec("insert ignore into t set id = 6, a = 6,    b = NULL;")
+	tk.MustQuery("show warnings").Check(testkit.Rows("Warning 1048 Column 'b' cannot be null"))
+	tk.MustExec("insert ignore into t set id = 7, a = DEFAULT, b = DEFAULT;")
+	tk.MustQuery("show warnings").Check(testkit.Rows("Warning 1364 Field 'a' doesn't have a default value"))
+	tk.MustQuery("select * from t order by id").Check(testkit.Rows("4 0 a", "5 0 ", "6 6 ", "7 0 a"))
+
+	// Test add column with OriginDefaultValue case.
+	tk.MustExec("drop table t")
+	tk.MustExec("create table t (id int, unique key idx (id))")
+	tk.MustExec("insert into t values (1)")
+	tk.MustExec("alter table t add column a int default 1")
+	tk.MustExec("alter table t add column b int default null")
+	tk.MustExec("alter table t add column c int not null")
+	tk.MustExec("alter table t add column d int not null default 1")
+	tk.MustExec("insert ignore into t (id) values (2)")
+	tk.MustQuery("show warnings").Check(testkit.Rows("Warning 1364 Field 'c' doesn't have a default value"))
+	tk.MustExec("insert ignore into t (id) values (1),(2) on duplicate key update id = id+10")
+	tk.MustQuery("show warnings").Check(testkit.Rows("Warning 1364 Field 'c' doesn't have a default value"))
+	tk.MustExec("alter table t alter column a drop default")
+	tk.MustExec("alter table t alter column b drop default")
+	tk.MustExec("alter table t alter column c drop default")
+	tk.MustExec("alter table t alter column d drop default")
+	tk.MustExec("insert ignore into t (id) values (3)")
+	tk.MustQuery("show warnings").Check(testkit.Rows("Warning 1364 Field 'a' doesn't have a default value", "Warning 1364 Field 'b' doesn't have a default value", "Warning 1364 Field 'c' doesn't have a default value", "Warning 1364 Field 'd' doesn't have a default value"))
+	tk.MustExec("insert ignore into t (id) values (11),(12),(3) on duplicate key update id = id+10")
+	tk.MustQuery("show warnings").Check(testkit.Rows("Warning 1364 Field 'a' doesn't have a default value", "Warning 1364 Field 'b' doesn't have a default value", "Warning 1364 Field 'c' doesn't have a default value", "Warning 1364 Field 'd' doesn't have a default value"))
+	tk.MustQuery("select * from t order by id").Check(testkit.Rows("13 <nil> <nil> 0 0", "21 1 <nil> 0 1", "22 1 <nil> 0 1"))
+>>>>>>> 7b2d727c0e9 (table: fix issue of get default value from column when column doesn't have default value (#51309) (#51386)):executor/executor_test.go
 }

pkg/planner/core/expression_rewriter.go

@@ -2297,7 +2297,7 @@ func (er *expressionRewriter) evalDefaultExpr(v *ast.DefaultExpr) {
 		}
 	default:
 		// for other columns, just use what it is
-		val, er.err = er.b.getDefaultValue(col)
+		val, er.err = er.b.getDefaultValue(col, false)
 	}
 	if er.err != nil {
 		return

pkg/planner/core/planbuilder.go

@@ -3855,14 +3855,19 @@ func genAuthErrForGrantStmt(sctx sessionctx.Context, dbName string) error {
 	return ErrDBaccessDenied.FastGenByArgs(u, h, dbName)
 }
 
-func (b *PlanBuilder) getDefaultValue(col *table.Column) (*expression.Constant, error) {
+func (b *PlanBuilder) getDefaultValue(col *table.Column, isInsert bool) (*expression.Constant, error) {
 	var (
 		value types.Datum
 		err   error
 	)
 	if col.DefaultIsExpr && col.DefaultExpr != nil {
 		value, err = table.EvalColDefaultExpr(b.ctx, col.ToInfo(), col.DefaultExpr)
 	} else {
+		if isInsert {
+			if err := table.CheckNoDefaultValueForInsert(b.ctx.GetSessionVars().StmtCtx, col.ToInfo()); err != nil {
+				return nil, err
+			}
+		}
 		value, err = table.GetColDefaultValue(b.ctx, col.ToInfo())
 	}
 	if err != nil {
@@ -4151,7 +4156,7 @@ func (b PlanBuilder) getInsertColExpr(ctx context.Context, insertPlan *Insert, m
 			// See note in the end of the function. Only default for generated columns are OK.
 			return nil, nil
 		}
-		outExpr, err = b.getDefaultValue(refCol)
+		outExpr, err = b.getDefaultValue(refCol, true)
 	case *driver.ValueExpr:
 		outExpr = &expression.Constant{
 			Value:   x.Datum,

pkg/table/column.go

@@ -529,6 +529,22 @@ func GetColOriginDefaultValueWithoutStrictSQLMode(ctx sessionctx.Context, col *m
 	})
 }
 
+// CheckNoDefaultValueForInsert checks if the column has no default value before insert data.
+// CheckNoDefaultValueForInsert extracts the check logic from getColDefaultValueFromNil,
+// since getColDefaultValueFromNil function is public path and both read/write and other places use it.
+// But CheckNoDefaultValueForInsert logic should only check before insert.
+func CheckNoDefaultValueForInsert(sc *stmtctx.StatementContext, col *model.ColumnInfo) error {
+	if mysql.HasNoDefaultValueFlag(col.GetFlag()) && !col.DefaultIsExpr && col.GetDefaultValue() == nil && col.GetType() != mysql.TypeEnum {
+		if !sc.BadNullAsWarning {
+			return ErrNoDefaultValue.GenWithStackByArgs(col.Name)
+		}
+		if !mysql.HasNotNullFlag(col.GetFlag()) {
+			sc.AppendWarning(ErrNoDefaultValue.FastGenByArgs(col.Name))
+		}
+	}
+	return nil
+}
+
 // GetColDefaultValue gets default value of the column.
 func GetColDefaultValue(ctx sessionctx.Context, col *model.ColumnInfo) (types.Datum, error) {
 	defaultValue := col.GetDefaultValue()
@@ -617,22 +633,19 @@ func getColDefaultValue(ctx sessionctx.Context, col *model.ColumnInfo, defaultVa
 }
 
 func getColDefaultValueFromNil(ctx sessionctx.Context, col *model.ColumnInfo, args *getColOriginDefaultValue) (types.Datum, error) {
-	if !mysql.HasNotNullFlag(col.GetFlag()) && !mysql.HasNoDefaultValueFlag(col.GetFlag()) {
+	if !mysql.HasNotNullFlag(col.GetFlag()) {
 		return types.Datum{}, nil
 	}
 	if col.GetType() == mysql.TypeEnum {
 		// For enum type, if no default value and not null is set,
 		// the default value is the first element of the enum list
-		if mysql.HasNotNullFlag(col.GetFlag()) {
-			defEnum, err := types.ParseEnumValue(col.FieldType.GetElems(), 1)
-			if err != nil {
-				return types.Datum{}, err
-			}
-			return types.NewCollateMysqlEnumDatum(defEnum, col.GetCollate()), nil
+		defEnum, err := types.ParseEnumValue(col.FieldType.GetElems(), 1)
+		if err != nil {
+			return types.Datum{}, err
 		}
-		return types.Datum{}, nil
+		return types.NewCollateMysqlEnumDatum(defEnum, col.GetCollate()), nil
 	}
-	if mysql.HasAutoIncrementFlag(col.GetFlag()) && !mysql.HasNoDefaultValueFlag(col.GetFlag()) {
+	if mysql.HasAutoIncrementFlag(col.GetFlag()) {
 		// Auto increment column doesn't have default value and we should not return error.
 		return GetZeroValue(col), nil
 	}
@@ -646,15 +659,16 @@ func getColDefaultValueFromNil(ctx sessionctx.Context, col *model.ColumnInfo, ar
 	}
 	if !strictSQLMode {
 		sc.AppendWarning(ErrNoDefaultValue.FastGenByArgs(col.Name))
-		if mysql.HasNotNullFlag(col.GetFlag()) {
-			return GetZeroValue(col), nil
-		}
-		if mysql.HasNoDefaultValueFlag(col.GetFlag()) {
-			return types.Datum{}, nil
-		}
+		return GetZeroValue(col), nil
 	}
 	if sc.BadNullAsWarning {
-		sc.AppendWarning(ErrColumnCantNull.FastGenByArgs(col.Name))
+		var err error
+		if mysql.HasNoDefaultValueFlag(col.GetFlag()) {
+			err = ErrNoDefaultValue.FastGenByArgs(col.Name)
+		} else {
+			err = ErrColumnCantNull.FastGenByArgs(col.Name)
+		}
+		sc.AppendWarning(err)
 		return GetZeroValue(col), nil
 	}
 	return types.Datum{}, ErrNoDefaultValue.GenWithStackByArgs(col.Name)