expression: fix "values" function in non-insert statement (#8019) (#8169

)

expression/builtin_other.go

@@ -512,6 +512,9 @@ func (b *builtinValuesIntSig) Clone() builtinFunc {
 // evalInt evals a builtinValuesIntSig.
 // See https://dev.mysql.com/doc/refman/5.7/en/miscellaneous-functions.html#function_values
 func (b *builtinValuesIntSig) evalInt(_ chunk.Row) (int64, bool, error) {
+	if !b.ctx.GetSessionVars().StmtCtx.InInsertStmt {
+		return 0, true, nil
+	}
 	row := b.ctx.GetSessionVars().CurrInsertValues
 	if row.IsEmpty() {
 		return 0, true, errors.New("Session current insert values is nil")
@@ -540,6 +543,9 @@ func (b *builtinValuesRealSig) Clone() builtinFunc {
 // evalReal evals a builtinValuesRealSig.
 // See https://dev.mysql.com/doc/refman/5.7/en/miscellaneous-functions.html#function_values
 func (b *builtinValuesRealSig) evalReal(_ chunk.Row) (float64, bool, error) {
+	if !b.ctx.GetSessionVars().StmtCtx.InInsertStmt {
+		return 0, true, nil
+	}
 	row := b.ctx.GetSessionVars().CurrInsertValues
 	if row.IsEmpty() {
 		return 0, true, errors.New("Session current insert values is nil")
@@ -568,6 +574,9 @@ func (b *builtinValuesDecimalSig) Clone() builtinFunc {
 // evalDecimal evals a builtinValuesDecimalSig.
 // See https://dev.mysql.com/doc/refman/5.7/en/miscellaneous-functions.html#function_values
 func (b *builtinValuesDecimalSig) evalDecimal(_ chunk.Row) (*types.MyDecimal, bool, error) {
+	if !b.ctx.GetSessionVars().StmtCtx.InInsertStmt {
+		return nil, true, nil
+	}
 	row := b.ctx.GetSessionVars().CurrInsertValues
 	if row.IsEmpty() {
 		return nil, true, errors.New("Session current insert values is nil")
@@ -596,6 +605,9 @@ func (b *builtinValuesStringSig) Clone() builtinFunc {
 // evalString evals a builtinValuesStringSig.
 // See https://dev.mysql.com/doc/refman/5.7/en/miscellaneous-functions.html#function_values
 func (b *builtinValuesStringSig) evalString(_ chunk.Row) (string, bool, error) {
+	if !b.ctx.GetSessionVars().StmtCtx.InInsertStmt {
+		return "", true, nil
+	}
 	row := b.ctx.GetSessionVars().CurrInsertValues
 	if row.IsEmpty() {
 		return "", true, errors.New("Session current insert values is nil")
@@ -624,6 +636,9 @@ func (b *builtinValuesTimeSig) Clone() builtinFunc {
 // evalTime evals a builtinValuesTimeSig.
 // See https://dev.mysql.com/doc/refman/5.7/en/miscellaneous-functions.html#function_values
 func (b *builtinValuesTimeSig) evalTime(_ chunk.Row) (types.Time, bool, error) {
+	if !b.ctx.GetSessionVars().StmtCtx.InInsertStmt {
+		return types.Time{}, true, nil
+	}
 	row := b.ctx.GetSessionVars().CurrInsertValues
 	if row.IsEmpty() {
 		return types.Time{}, true, errors.New("Session current insert values is nil")
@@ -652,6 +667,9 @@ func (b *builtinValuesDurationSig) Clone() builtinFunc {
 // evalDuration evals a builtinValuesDurationSig.
 // See https://dev.mysql.com/doc/refman/5.7/en/miscellaneous-functions.html#function_values
 func (b *builtinValuesDurationSig) evalDuration(_ chunk.Row) (types.Duration, bool, error) {
+	if !b.ctx.GetSessionVars().StmtCtx.InInsertStmt {
+		return types.Duration{}, true, nil
+	}
 	row := b.ctx.GetSessionVars().CurrInsertValues
 	if row.IsEmpty() {
 		return types.Duration{}, true, errors.New("Session current insert values is nil")
@@ -681,6 +699,9 @@ func (b *builtinValuesJSONSig) Clone() builtinFunc {
 // evalJSON evals a builtinValuesJSONSig.
 // See https://dev.mysql.com/doc/refman/5.7/en/miscellaneous-functions.html#function_values
 func (b *builtinValuesJSONSig) evalJSON(_ chunk.Row) (json.BinaryJSON, bool, error) {
+	if !b.ctx.GetSessionVars().StmtCtx.InInsertStmt {
+		return json.BinaryJSON{}, true, nil
+	}
 	row := b.ctx.GetSessionVars().CurrInsertValues
 	if row.IsEmpty() {
 		return json.BinaryJSON{}, true, errors.New("Session current insert values is nil")

expression/builtin_other_test.go

@@ -14,7 +14,6 @@
 package expression
 
 import (
-	"fmt"
 	"math"
 	"time"
 
@@ -202,20 +201,35 @@ func (s *testEvaluatorSuite) TestGetVar(c *C) {
 
 func (s *testEvaluatorSuite) TestValues(c *C) {
 	defer testleak.AfterTest(c)()
+
+	origin := s.ctx.GetSessionVars().StmtCtx.InInsertStmt
+	s.ctx.GetSessionVars().StmtCtx.InInsertStmt = false
+	defer func() {
+		s.ctx.GetSessionVars().StmtCtx.InInsertStmt = origin
+	}()
+
 	fc := &valuesFunctionClass{baseFunctionClass{ast.Values, 0, 0}, 1, types.NewFieldType(mysql.TypeVarchar)}
 	_, err := fc.getFunction(s.ctx, s.datumsToConstants(types.MakeDatums("")))
 	c.Assert(err, ErrorMatches, "*Incorrect parameter count in the call to native function 'values'")
+
 	sig, err := fc.getFunction(s.ctx, s.datumsToConstants(types.MakeDatums()))
 	c.Assert(err, IsNil)
-	_, err = evalBuiltinFunc(sig, chunk.Row{})
-	c.Assert(err.Error(), Equals, "Session current insert values is nil")
+
+	ret, err := evalBuiltinFunc(sig, chunk.Row{})
+	c.Assert(err, IsNil)
+	c.Assert(ret.IsNull(), IsTrue)
+
 	s.ctx.GetSessionVars().CurrInsertValues = chunk.MutRowFromDatums(types.MakeDatums("1")).ToRow()
-	_, err = evalBuiltinFunc(sig, chunk.Row{})
-	c.Assert(err.Error(), Equals, fmt.Sprintf("Session current insert values len %d and column's offset %v don't match", 1, 1))
+	ret, err = evalBuiltinFunc(sig, chunk.Row{})
+	c.Assert(err, IsNil)
+	c.Assert(ret.IsNull(), IsTrue)
+
 	currInsertValues := types.MakeDatums("1", "2")
+	s.ctx.GetSessionVars().StmtCtx.InInsertStmt = true
 	s.ctx.GetSessionVars().CurrInsertValues = chunk.MutRowFromDatums(currInsertValues).ToRow()
-	ret, err := evalBuiltinFunc(sig, chunk.Row{})
+	ret, err = evalBuiltinFunc(sig, chunk.Row{})
 	c.Assert(err, IsNil)
+
 	cmp, err := ret.CompareDatum(nil, &currInsertValues[1])
 	c.Assert(err, IsNil)
 	c.Assert(cmp, Equals, 0)

expression/integration_test.go

@@ -3604,3 +3604,13 @@ func (s *testIntegrationSuite) TestDecimalMul(c *C) {
 	res := tk.MustQuery("select * from t;")
 	res.Check(testkit.Rows("0.55125221922461136"))
 }
+
+func (s *testIntegrationSuite) TestValuesInNonInsertStmt(c *C) {
+	tk := testkit.NewTestKit(c, s.store)
+	tk.MustExec(`use test;`)
+	tk.MustExec(`drop table if exists t;`)
+	tk.MustExec(`create table t(a bigint, b double, c decimal, d varchar(20), e datetime, f time, g json);`)
+	tk.MustExec(`insert into t values(1, 1.1, 2.2, "abc", "2018-10-24", NOW(), "12");`)
+	res := tk.MustQuery(`select values(a), values(b), values(c), values(d), values(e), values(f), values(g) from t;`)
+	res.Check(testkit.Rows(`<nil> <nil> <nil> <nil> <nil> <nil> <nil>`))
+}