Merge pull request #161 from pingcap/siddontang/fix-unary-bool

expressions,tidb: unary handes bool type

expression/expressions/unary.go

@@ -164,6 +164,11 @@ func (u *UnaryOperation) Eval(ctx context.Context, args map[interface{}]interfac
 		switch x := a.(type) {
 		case nil:
 			return nil, nil
+		case bool:
+			if x {
+				return int64(1), nil
+			}
+			return int64(0), nil
 		case float32:
 			return +x, nil
 		case float64:
@@ -209,6 +214,11 @@ func (u *UnaryOperation) Eval(ctx context.Context, args map[interface{}]interfac
 		switch x := a.(type) {
 		case nil:
 			return nil, nil
+		case bool:
+			if x {
+				return int64(-1), nil
+			}
+			return int64(0), nil
 		case float32:
 			return -x, nil
 		case float64:

expression/expressions/unary_test.go

@@ -55,6 +55,8 @@ func (s *testUnaryOperationSuite) TestUnaryOp(c *C) {
 		{"1.0", opcode.Plus, "1.0"},
 		{[]byte("1.0"), opcode.Plus, []byte("1.0")},
 		{mysql.Hex{Value: 1}, opcode.Plus, mysql.Hex{Value: 1}},
+		{true, opcode.Plus, int64(1)},
+		{false, opcode.Plus, int64(0)},
 
 		// test Minus.
 		{nil, opcode.Minus, nil},
@@ -70,6 +72,8 @@ func (s *testUnaryOperationSuite) TestUnaryOp(c *C) {
 		{"1.0", opcode.Minus, -1.0},
 		{[]byte("1.0"), opcode.Minus, -1.0},
 		{mysql.Hex{Value: 1}, opcode.Minus, -1.0},
+		{true, opcode.Minus, int64(-1)},
+		{false, opcode.Minus, int64(0)},
 	}
 
 	for _, t := range tbl {
@@ -150,9 +154,7 @@ func (s *testUnaryOperationSuite) TestUnaryOp(c *C) {
 		{mockExpr{}, opcode.Not},
 		{mockExpr{}, opcode.BitNeg},
 		{mockExpr{}, opcode.Plus},
-		{false, opcode.Plus},
 		{mockExpr{}, opcode.Minus},
-		{false, opcode.Minus},
 		{mockExpr{}, opcode.EQ},
 	}
 

tidb_test.go

@@ -678,6 +678,16 @@ func (s *testSessionSuite) TestHexadecimal(c *C) {
 	match(c, row, 2, 1)
 }
 
+func (s *testSessionSuite) TestExpression(c *C) {
+	store := newStore(c, s.dbName)
+	se := newSession(c, store, s.dbName)
+
+	r := mustExecSQL(c, se, `select + (1 > 0), -(1 >0), + (1 < 0), - (1 < 0)`)
+	row, err := r.FirstRow()
+	c.Assert(err, IsNil)
+	match(c, row, 1, -1, 0, 0)
+}
+
 func newSession(c *C, store kv.Storage, dbName string) Session {
 	se, err := CreateSession(store)
 	c.Assert(err, IsNil)