From fcc15b1256e4e33132a80e39b841a6e062c353a0 Mon Sep 17 00:00:00 2001
From: DQYuan <932087612@qq.com>
Date: Tue, 16 Jul 2019 19:50:04 +0800
Subject: [PATCH] types: fix delete error when convert string to float or int
 (#10861)

---
 executor/executor_test.go |  1 +
 types/convert.go          |  4 ++++
 types/convert_test.go     | 23 +++++++++++++++++++++++
 3 files changed, 28 insertions(+)

diff --git a/executor/executor_test.go b/executor/executor_test.go
index b68bebd4bfefb..7bd75859cdaf7 100644
--- a/executor/executor_test.go
+++ b/executor/executor_test.go
@@ -451,6 +451,7 @@ 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(context.Background(), tt.data1, tt.data2)
 		c.Assert(err1, IsNil)
 		c.Assert(reachLimit, IsFalse)
diff --git a/types/convert.go b/types/convert.go
index 58913cb2252eb..7ddfa5e1dd2b1 100644
--- a/types/convert.go
+++ b/types/convert.go
@@ -581,6 +581,10 @@ 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
diff --git a/types/convert_test.go b/types/convert_test.go
index 47f13e99306ad..52e1b58832683 100644
--- a/types/convert_test.go
+++ b/types/convert_test.go
@@ -461,6 +461,29 @@ 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) {