executor: set length and frac when we change zero to decimal t… (#16518)

executor/executor_test.go

@@ -5397,3 +5397,13 @@ func (s *testSuite1) TestIssue15767(c *C) {
 	tk.MustExec("insert into t select * from t;")
 	tk.MustQuery("select b, count(*) from ( select b from t order by a limit 20 offset 2) as s group by b order by b;").Check(testkit.Rows("a 6", "c 7", "s 7"))
 }
+
+func (s *testSuite1) TestIssue16025(c *C) {
+	tk := testkit.NewTestKit(c, s.store)
+	tk.MustExec("use test;")
+	tk.MustExec("drop table if exists t0;")
+	tk.MustExec("CREATE TABLE t0(c0 NUMERIC PRIMARY KEY);")
+	tk.MustExec("INSERT IGNORE INTO t0(c0) VALUES (NULL);")
+	tk.MustQuery("SELECT * FROM t0 WHERE c0;").Check(testkit.Rows())
+
+}

executor/insert_test.go

@@ -1132,3 +1132,14 @@ func (s *testSuite9) TestInsertErrorMsg(c *C) {
 	c.Assert(err, NotNil)
 	c.Assert(strings.Contains(err.Error(), "Incorrect datetime value: '2019-02-11 30:00:00' for column 'b' at row 1"), IsTrue, Commentf("%v", err))
 }
+
+func (s *testSuite9) TestIssue16366(c *C) {
+	tk := testkit.NewTestKit(c, s.store)
+	tk.MustExec(`use test;`)
+	tk.MustExec(`drop table if exists t;`)
+	tk.MustExec(`create table t(c numeric primary key);`)
+	tk.MustExec("insert ignore into t values(null);")
+	_, err := tk.Exec(`insert into t values(0);`)
+	c.Assert(err, NotNil)
+	c.Assert(strings.Contains(err.Error(), "Duplicate entry '0' for key 'PRIMARY'"), IsTrue, Commentf("%v", err))
+}

table/column.go

@@ -505,6 +505,8 @@ func GetZeroValue(col *model.ColumnInfo) types.Datum {
 	case mysql.TypeDouble:
 		d.SetFloat64(0)
 	case mysql.TypeNewDecimal:
+		d.SetLength(col.Flen)
+		d.SetFrac(col.Decimal)
 		d.SetMysqlDecimal(new(types.MyDecimal))
 	case mysql.TypeString:
 		if col.Flen > 0 && col.Charset == charset.CharsetBin {