xapi/xeval: fix AND OR evaluator. (pingcap#1076)

* xapi/xeval: fix AND OR evaluator. * *: simplify code.
indescribable · Apr 10, 2016 · 7e27211 · 7e27211
1 parent 8d9bf2f
commit 7e27211
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Showing 2 changed files with 35 additions and 5 deletions.
diff --git a/xapi/xeval/eval.go b/xapi/xeval/eval.go
@@ -249,21 +249,35 @@ func (e *Evaluator) evalAnd(expr *tipb.Expr) (types.Datum, error) {
 	if err != nil {
 		return types.Datum{}, errors.Trace(err)
 	}
-	if leftBool == 1 && rightBool == 1 {
-		return types.NewIntDatum(1), nil
+	var d types.Datum
+	if leftBool == 0 || rightBool == 0 {
+		d.SetInt64(0)
+		return d, nil
 	}
-	return types.NewIntDatum(0), nil
+	if leftBool == compareResultNull || rightBool == compareResultNull {
+		d.SetNull()
+		return d, nil
+	}
+	d.SetInt64(1)
+	return d, nil
 }
 
 func (e *Evaluator) evalOr(expr *tipb.Expr) (types.Datum, error) {
 	leftBool, rightBool, err := e.evalTwoBoolChildren(expr)
 	if err != nil {
 		return types.Datum{}, errors.Trace(err)
 	}
+	var d types.Datum
 	if leftBool == 1 || rightBool == 1 {
-		return types.NewIntDatum(1), nil
+		d.SetInt64(1)
+		return d, nil
 	}
-	return types.NewIntDatum(0), nil
+	if leftBool == compareResultNull || rightBool == compareResultNull {
+		d.SetNull()
+		return d, nil
+	}
+	d.SetInt64(0)
+	return d, nil
 }
 
 func (e *Evaluator) evalTwoBoolChildren(expr *tipb.Expr) (leftBool, rightBool int64, err error) {

diff --git a/xapi/xeval/eval_test.go b/xapi/xeval/eval_test.go
@@ -167,6 +167,14 @@ func (s *testEvalSuite) TestEval(c *C) {
 			binaryExpr(types.NewIntDatum(1), types.NewIntDatum(1), tipb.ExprType_And),
 			types.NewIntDatum(1),
 		},
+		{
+			binaryExpr(types.NewIntDatum(0), types.Datum{}, tipb.ExprType_And),
+			types.NewIntDatum(0),
+		},
+		{
+			binaryExpr(types.NewIntDatum(1), types.Datum{}, tipb.ExprType_And),
+			types.Datum{},
+		},
 		{
 			binaryExpr(types.NewIntDatum(0), types.NewIntDatum(0), tipb.ExprType_Or),
 			types.NewIntDatum(0),
@@ -175,6 +183,14 @@ func (s *testEvalSuite) TestEval(c *C) {
 			binaryExpr(types.NewIntDatum(0), types.NewIntDatum(1), tipb.ExprType_Or),
 			types.NewIntDatum(1),
 		},
+		{
+			binaryExpr(types.NewIntDatum(0), types.Datum{}, tipb.ExprType_Or),
+			types.Datum{},
+		},
+		{
+			binaryExpr(types.NewIntDatum(1), types.Datum{}, tipb.ExprType_Or),
+			types.NewIntDatum(1),
+		},
 		{
 			binaryExpr(
 				binaryExpr(types.NewIntDatum(1), types.NewIntDatum(1), tipb.ExprType_EQ),