expression: base #3868 pr, and rewrite builtin function unary minus t…

…o handle overflow gracely
pingcap · Jul 25, 2017 · b305a4f · b305a4f
1 parent 869e1f6
commit b305a4f
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Showing 4 changed files with 17 additions and 31 deletions.
diff --git a/executor/aggregate_test.go b/executor/aggregate_test.go
@@ -318,6 +318,7 @@ func (s *testSuite) TestAggPrune(c *C) {
 		testleak.AfterTest(c)()
 	}()
 	tk := testkit.NewTestKit(c, s.store)
+
 	tk.MustExec("use test")
 	tk.MustExec("drop table if exists t")
 	tk.MustExec("create table t(id int primary key, b varchar(50), c int)")

diff --git a/executor/prepared.go b/executor/prepared.go
@@ -349,6 +349,7 @@ func ResetStmtCtx(ctx context.Context, s ast.StmtNode) {
 		sc.TruncateAsWarning = !sessVars.StrictSQLMode
 	case *ast.SelectStmt:
 		sc.InSelectStmt = true
+		sc.IgnoreTruncate = true
 	default:
 		sc.IgnoreTruncate = true
 		if show, ok := s.(*ast.ShowStmt); ok {

diff --git a/expression/builtin_op_test.go b/expression/builtin_op_test.go
@@ -33,19 +33,29 @@ func (s *testEvaluatorSuite) TestUnary(c *C) {
 	}{
 		{uint64(9223372036854775809), "-9223372036854775809", true, false},
 		{uint64(9223372036854775810), "-9223372036854775810", true, false},
-		{uint64(9223372036854775808), -9223372036854775808, false, false},
+		{uint64(9223372036854775808), int64(-9223372036854775808), false, false},
 		{int64(math.MinInt64), "9223372036854775808", true, false}, // --9223372036854775808
 	}
+	sc := s.ctx.GetSessionVars().StmtCtx
+	origin := sc.InSelectStmt
+	sc.InSelectStmt = true
+	defer func() {
+		sc.InSelectStmt = origin
+	}()
 
 	for _, t := range cases {
 		f, err := newFunctionForTest(s.ctx, ast.UnaryMinus, primitiveValsToConstants([]interface{}{t.args})...)
 		c.Assert(err, IsNil)
 		d, err := f.Eval(nil)
-
-		if !t.overflow {
-			c.Assert(d.GetValue(), Equals, t.expected)
+		if t.getErr == false {
+			c.Assert(err, IsNil)
+			if !t.overflow {
+				c.Assert(d.GetValue(), Equals, t.expected)
+			} else {
+				c.Assert(d.GetMysqlDecimal().String(), Equals, t.expected)
+			}
 		} else {
-			c.Assert(d.GetMysqlDecimal().String(), Equals, t.expected)
+			c.Assert(err, NotNil)
 		}
 	}
 }

diff --git a/expression/scalar_function.go b/expression/scalar_function.go
@@ -23,7 +23,6 @@ import (
 	"github.com/pingcap/tidb/model"
 	"github.com/pingcap/tidb/mysql"
 	"github.com/pingcap/tidb/sessionctx/variable"
-	"github.com/pingcap/tidb/terror"
 	"github.com/pingcap/tidb/util/codec"
 	"github.com/pingcap/tidb/util/types"
 )
@@ -161,21 +160,6 @@ func (sf *ScalarFunction) Decorrelate(schema *Schema) Expression {
 	return sf
 }
 
-func (sf *ScalarFunction) convertArgsToDecimal(sc *variable.StatementContext) error {
-	ft := types.NewFieldType(mysql.TypeNewDecimal)
-	for _, arg := range sf.GetArgs() {
-		if constArg, ok := arg.(*Constant); ok {
-			val, err := constArg.Value.ConvertTo(sc, ft)
-			if err != nil {
-				return errors.Trace(err)
-			}
-			constArg.Value = val
-		}
-	}
-
-	return nil
-}
-
 // Eval implements Expression interface.
 func (sf *ScalarFunction) Eval(row []types.Datum) (d types.Datum, err error) {
 	sc := sf.GetCtx().GetSessionVars().StmtCtx
@@ -213,16 +197,6 @@ func (sf *ScalarFunction) Eval(row []types.Datum) (d types.Datum, err error) {
 		}
 	}
 
-	if err != nil && terror.ErrorEqual(err, types.ErrOverflow) &&
-		sf.FuncName.L == ast.UnaryMinus && sc.InSelectStmt {
-		// TODO: fix #3762, overflow convert it to decimal
-		err = sf.convertArgsToDecimal(sc)
-		if err != nil {
-			return d, errors.Trace(err)
-		}
-		res, isNull, err = sf.EvalDecimal(row, sc)
-	}
-
 	if isNull || err != nil {
 		d.SetValue(nil)
 		return d, errors.Trace(err)