types: fix insert error when convert string to float (#13716)

executor/insert_test.go

@@ -770,3 +770,24 @@ func (s *testSuite3) TestJiraIssue5366(c *C) {
 	tk.MustExec(` insert into bug select  ifnull(JSON_UNQUOTE(JSON_EXTRACT('[{"amount":2000,"feeAmount":0,"merchantNo":"20190430140319679394","shareBizCode":"20160311162_SECOND"}]', '$[0].merchantNo')),'') merchant_no union SELECT '20180531557' merchant_no;`)
 	tk.MustQuery(`select * from bug`).Sort().Check(testkit.Rows("20180531557", "20190430140319679394"))
 }
+
+func (s *testSuite3) TestDMLCast(c *C) {
+	tk := testkit.NewTestKit(c, s.store)
+	tk.MustExec(`use test`)
+	tk.MustExec(`create table t (a int, b double)`)
+	tk.MustExec(`insert into t values (ifnull('',0)+0, 0)`)
+	tk.MustExec(`insert into t values (0, ifnull('',0)+0)`)
+	tk.MustQuery(`select * from t`).Check(testkit.Rows("0 0", "0 0"))
+	_, err := tk.Exec(`insert into t values ('', 0)`)
+	c.Assert(err, NotNil)
+	_, err = tk.Exec(`insert into t values (0, '')`)
+	c.Assert(err, NotNil)
+	_, err = tk.Exec(`update t set a = ''`)
+	c.Assert(err, NotNil)
+	_, err = tk.Exec(`update t set b = ''`)
+	c.Assert(err, NotNil)
+	tk.MustExec("update t set a = ifnull('',0)+0")
+	tk.MustExec("update t set b = ifnull('',0)+0")
+	tk.MustExec("delete from t where a = ''")
+	tk.MustQuery(`select * from t`).Check(testkit.Rows())
+}

executor/write_test.go

@@ -1498,7 +1498,7 @@ func (s *testSuite) TestUpdate(c *C) {
 	tk.MustExec("update t set a = ''")
 	tk.MustQuery("select * from t").Check(testkit.Rows("0000-00-00 00:00:00 1999-12-13 00:00:00"))
 	tk.MustExec("update t set b = ''")
-	tk.MustQuery("select * from t").Check(testkit.Rows("0000-00-00 00:00:00 <nil>"))
+	tk.MustQuery("select * from t").Check(testkit.Rows("0000-00-00 00:00:00 0000-00-00 00:00:00"))
 	tk.MustExec("set @@sql_mode=@orig_sql_mode;")
 
 	tk.MustExec("create view v as select * from t")

expression/builtin_cast.go

@@ -1095,6 +1095,10 @@ func (b *builtinCastStringAsIntSig) evalInt(row chunk.Row) (res int64, isNull bo
 	if len(val) > 1 && val[0] == '-' { // negative number
 		isNegative = true
 	}
+	sctx := b.ctx.GetSessionVars().StmtCtx
+	if val == "" && (sctx.InInsertStmt || sctx.InUpdateStmt) {
+		return 0, false, nil
+	}
 
 	var ures uint64
 	sc := b.ctx.GetSessionVars().StmtCtx
@@ -1137,6 +1141,10 @@ func (b *builtinCastStringAsRealSig) evalReal(row chunk.Row) (res float64, isNul
 	if isNull || err != nil {
 		return res, isNull, err
 	}
+	sctx := b.ctx.GetSessionVars().StmtCtx
+	if val == "" && (sctx.InInsertStmt || sctx.InUpdateStmt) {
+		return 0, false, nil
+	}
 	sc := b.ctx.GetSessionVars().StmtCtx
 	res, err = types.StrToFloat(sc, val)
 	if err != nil {

planner/core/logical_plan_builder.go

@@ -2753,7 +2753,6 @@ func (b *PlanBuilder) buildUpdateLists(ctx context.Context, tableList []*ast.Tab
 		if err != nil {
 			return nil, nil, err
 		}
-		newExpr = expression.BuildCastFunction(b.ctx, newExpr, col.GetType())
 		p = np
 		newList = append(newList, &expression.Assignment{Col: col, Expr: newExpr})
 	}

types/convert.go

@@ -618,7 +618,7 @@ func ConvertJSONToDecimal(sc *stmtctx.StatementContext, j json.BinaryJSON) (*MyD
 
 // getValidFloatPrefix gets prefix of string which can be successfully parsed as float.
 func getValidFloatPrefix(sc *stmtctx.StatementContext, s string) (valid string, err error) {
-	if (sc.InDeleteStmt || sc.InSelectStmt || sc.InUpdateStmt) && s == "" {
+	if (sc.InDeleteStmt || sc.InSelectStmt) && s == "" {
 		return "0", nil
 	}
 	var (

types/convert_test.go

@@ -469,17 +469,14 @@ func (s *testTypeConvertSuite) TestStrToNum(c *C) {
 func testSelectUpdateDeleteEmptyStringError(c *C) {
 	testCases := []struct {
 		inSelect bool
-		inUpdate bool
 		inDelete bool
 	}{
-		{true, false, false},
-		{false, true, false},
-		{false, false, true},
+		{true, false},
+		{false, true},
 	}
 	sc := new(stmtctx.StatementContext)
 	for _, tc := range testCases {
 		sc.InSelectStmt = tc.inSelect
-		sc.InUpdateStmt = tc.inUpdate
 		sc.InDeleteStmt = tc.inDelete
 
 		str := ""