types: fix string to integer cast (#11295)

executor/executor.go

@@ -1395,8 +1395,10 @@ func ResetContextOfStmt(ctx sessionctx.Context, s ast.StmtNode) (err error) {
 			sc.NotFillCache = !opts.SQLCache
 		}
 		sc.PadCharToFullLength = ctx.GetSessionVars().SQLMode.HasPadCharToFullLengthMode()
+		sc.CastStrToIntStrict = true
 	case *ast.ExplainStmt:
 		sc.InExplainStmt = true
+		sc.CastStrToIntStrict = true
 	case *ast.ShowStmt:
 		sc.IgnoreTruncate = true
 		sc.IgnoreZeroInDate = true

executor/executor_test.go

@@ -363,6 +363,7 @@ 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)

executor/point_get_test.go

@@ -399,4 +399,6 @@ func (s *testPointGetSuite) TestIssue10677(c *C) {
 	tk.MustQuery("select * from t where pk = 1").Check(testkit.Rows("1"))
 	tk.MustQuery("desc select * from t where pk = '1'").Check(testkit.Rows("Point_Get_1 1.00 root table:t, handle:1"))
 	tk.MustQuery("select * from t where pk = '1'").Check(testkit.Rows("1"))
+	tk.MustQuery("desc select * from t where pk = '1.0'").Check(testkit.Rows("Point_Get_1 1.00 root table:t, handle:1"))
+	tk.MustQuery("select * from t where pk = '1.0'").Check(testkit.Rows("1"))
 }

expression/builtin_cast_test.go

@@ -88,7 +88,11 @@ func (s *testEvaluatorSuite) TestCast(c *C) {
 	c.Assert(terror.ErrorEqual(errWarnAllowedPacketOverflowed, lastWarn.Err), IsTrue, Commentf("err %v", lastWarn.Err))
 
 	origSc := sc
+	oldInSelectStmt := sc.InSelectStmt
 	sc.InSelectStmt = true
+	defer func() {
+		sc.InSelectStmt = oldInSelectStmt
+	}()
 	sc.OverflowAsWarning = true
 
 	// cast('18446744073709551616' as unsigned);

planner/core/point_get_plan.go

@@ -219,7 +219,10 @@ func tryPointGetPlan(ctx sessionctx.Context, selStmt *ast.SelectStmt) *PointGetP
 				p.IsTableDual = true
 				return p
 			}
-			return nil
+			// some scenarios cast to int with error, but we may use this value in point get
+			if !terror.ErrorEqual(types.ErrTruncatedWrongVal, err) {
+				return nil
+			}
 		}
 		cmp, err := intDatum.CompareDatum(ctx.GetSessionVars().StmtCtx, &handlePair.value)
 		if err != nil {

sessionctx/stmtctx/stmtctx.go

@@ -69,6 +69,11 @@ type StatementContext struct {
 	BatchCheck             bool
 	InNullRejectCheck      bool
 	AllowInvalidDate       bool
+	// CastStrToIntStrict is used to control the way we cast float format string to int.
+	// If ConvertStrToIntStrict is false, we convert it to a valid float string first,
+	// then cast the float string to int string. Otherwise, we cast string to integer
+	// prefix in a strict way, only extract 0-9 and (+ or - in first bit).
+	CastStrToIntStrict bool
 
 	// mu struct holds variables that change during execution.
 	mu struct {

types/convert.go

@@ -362,11 +362,37 @@ func NumberToDuration(number int64, fsp int) (Duration, error) {
 
 // getValidIntPrefix gets prefix of the string which can be successfully parsed as int.
 func getValidIntPrefix(sc *stmtctx.StatementContext, str string) (string, error) {
-	floatPrefix, err := getValidFloatPrefix(sc, str)
-	if err != nil {
-		return floatPrefix, errors.Trace(err)
+	if !sc.CastStrToIntStrict {
+		floatPrefix, err := getValidFloatPrefix(sc, str)
+		if err != nil {
+			return floatPrefix, errors.Trace(err)
+		}
+		return floatStrToIntStr(sc, floatPrefix, str)
+	}
+
+	validLen := 0
+
+	for i := 0; i < len(str); i++ {
+		c := str[i]
+		if (c == '+' || c == '-') && i == 0 {
+			continue
+		}
+
+		if c >= '0' && c <= '9' {
+			validLen = i + 1
+			continue
+		}
+
+		break
 	}
-	return floatStrToIntStr(sc, floatPrefix, str)
+	valid := str[:validLen]
+	if valid == "" {
+		valid = "0"
+	}
+	if validLen == 0 || validLen != len(str) {
+		return valid, errors.Trace(handleTruncateError(sc, ErrTruncatedWrongVal.GenWithStackByArgs("INTEGER", str)))
+	}
+	return valid, nil
 }
 
 // roundIntStr is to round a **valid int string** base on the number following dot.
@@ -587,6 +613,9 @@ 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 == "" {
+		return "0", nil
+	}
 	var (
 		sawDot   bool
 		sawDigit bool
@@ -627,7 +656,7 @@ func getValidFloatPrefix(sc *stmtctx.StatementContext, s string) (valid string,
 		valid = "0"
 	}
 	if validLen == 0 || validLen != len(s) {
-		err = errors.Trace(handleTruncateError(sc))
+		err = errors.Trace(handleTruncateError(sc, ErrTruncated))
 	}
 	return valid, err
 }

types/convert_test.go

@@ -461,6 +461,42 @@ 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, #11179
+	testSelectUpdateDeleteEmptyStringError(c)
+}
+
+func testSelectUpdateDeleteEmptyStringError(c *C) {
+	testCases := []struct {
+		inSelect bool
+		inUpdate bool
+		inDelete bool
+	}{
+		{true, false, false},
+		{false, true, false},
+		{false, false, true},
+	}
+	sc := new(stmtctx.StatementContext)
+	for _, tc := range testCases {
+		sc.InSelectStmt = tc.inSelect
+		sc.InUpdateStmt = tc.inUpdate
+		sc.InDeleteStmt = tc.inDelete
+
+		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) {
@@ -666,6 +702,80 @@ func (s *testTypeConvertSuite) TestConvert(c *C) {
 	signedAccept(c, mysql.TypeNewDecimal, dec, "-0.00123")
 }
 
+func (s *testTypeConvertSuite) TestGetValidInt(c *C) {
+	tests := []struct {
+		origin  string
+		valid   string
+		warning bool
+	}{
+		{"100", "100", false},
+		{"-100", "-100", false},
+		{"1abc", "1", true},
+		{"-1-1", "-1", true},
+		{"+1+1", "+1", true},
+		{"123..34", "123", true},
+		{"123.23E-10", "123", true},
+		{"1.1e1.3", "1", true},
+		{"11e1.3", "11", true},
+		{"1.", "1", true},
+		{".1", "0", true},
+		{"", "0", true},
+		{"123e+", "123", true},
+		{"123de", "123", true},
+	}
+	sc := new(stmtctx.StatementContext)
+	sc.TruncateAsWarning = true
+	sc.CastStrToIntStrict = true
+	warningCount := 0
+	for _, tt := range tests {
+		prefix, err := getValidIntPrefix(sc, tt.origin)
+		c.Assert(err, IsNil)
+		c.Assert(prefix, Equals, tt.valid)
+		_, err = strconv.ParseInt(prefix, 10, 64)
+		c.Assert(err, IsNil)
+		warnings := sc.GetWarnings()
+		if tt.warning {
+			c.Assert(warnings, HasLen, warningCount+1)
+			c.Assert(terror.ErrorEqual(warnings[len(warnings)-1].Err, ErrTruncatedWrongVal), IsTrue)
+			warningCount += 1
+		} else {
+			c.Assert(warnings, HasLen, warningCount)
+		}
+	}
+
+	tests2 := []struct {
+		origin  string
+		valid   string
+		warning bool
+	}{
+		{"100", "100", false},
+		{"-100", "-100", false},
+		{"1abc", "1", true},
+		{"-1-1", "-1", true},
+		{"+1+1", "+1", true},
+		{"123..34", "123.", true},
+		{"123.23E-10", "0", false},
+		{"1.1e1.3", "1.1e1", true},
+		{"11e1.3", "11e1", true},
+		{"1.", "1", false},
+		{".1", "0", false},
+		{"", "0", true},
+		{"123e+", "123", true},
+		{"123de", "123", true},
+	}
+	sc.TruncateAsWarning = false
+	sc.CastStrToIntStrict = false
+	for _, tt := range tests2 {
+		prefix, err := getValidIntPrefix(sc, tt.origin)
+		if tt.warning {
+			c.Assert(terror.ErrorEqual(err, ErrTruncated), IsTrue)
+		} else {
+			c.Assert(err, IsNil)
+		}
+		c.Assert(prefix, Equals, tt.valid)
+	}
+}
+
 func (s *testTypeConvertSuite) TestRoundIntStr(c *C) {
 	cases := []struct {
 		a string

types/datum.go

@@ -1781,14 +1781,14 @@ func (ds *datumsSorter) Swap(i, j int) {
 	ds.datums[i], ds.datums[j] = ds.datums[j], ds.datums[i]
 }
 
-func handleTruncateError(sc *stmtctx.StatementContext) error {
+func handleTruncateError(sc *stmtctx.StatementContext, err error) error {
 	if sc.IgnoreTruncate {
 		return nil
 	}
 	if !sc.TruncateAsWarning {
-		return ErrTruncated
+		return err
 	}
-	sc.AppendWarning(ErrTruncated)
+	sc.AppendWarning(err)
 	return nil
 }