fix delete empty string bug (pingcap#10861)

executor/executor_test.go

@@ -336,6 +336,7 @@ func checkCases(tests []testCase, ld *executor.LoadDataInfo,
 		ctx.GetSessionVars().StmtCtx.DupKeyAsWarning = true
 		ctx.GetSessionVars().StmtCtx.BadNullAsWarning = true
 		ctx.GetSessionVars().StmtCtx.InLoadDataStmt = true
+		ctx.GetSessionVars().StmtCtx.InDeleteStmt = false
 		data, reachLimit, err1 := ld.InsertData(tt.data1, tt.data2)
 		c.Assert(err1, IsNil)
 		c.Assert(reachLimit, IsFalse)

types/convert.go

@@ -550,6 +550,10 @@ 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 && s == "" {
+		return "0", nil
+	}
+
 	var (
 		sawDot   bool
 		sawDigit bool

types/convert_test.go

@@ -459,6 +459,29 @@ func (s *testTypeConvertSuite) TestStrToNum(c *C) {
 	testStrToFloat(c, "1e649", math.MaxFloat64, false, nil)
 	testStrToFloat(c, "-1e649", -math.MaxFloat64, true, ErrTruncatedWrongVal)
 	testStrToFloat(c, "-1e649", -math.MaxFloat64, false, nil)
+
+	// for issue  #10806
+	testDeleteEmptyStringError(c)
+}
+
+func testDeleteEmptyStringError(c *C) {
+	sc := new(stmtctx.StatementContext)
+	sc.InDeleteStmt = true
+
+	str := ""
+	expect := 0
+
+	val, err := StrToInt(sc, str)
+	c.Assert(err, IsNil)
+	c.Assert(val, Equals, int64(expect))
+
+	val1, err := StrToUint(sc, str)
+	c.Assert(err, IsNil)
+	c.Assert(val1, Equals, uint64(expect))
+
+	val2, err := StrToFloat(sc, str)
+	c.Assert(err, IsNil)
+	c.Assert(val2, Equals, float64(expect))
 }
 
 func (s *testTypeConvertSuite) TestFieldTypeToStr(c *C) {