*: use a const int value instead of string

soenter · Oct 30, 2015 · 480f7f3 · 480f7f3
1 parent 414ae7b
commit 480f7f3
Show file tree

Hide file tree

Showing 3 changed files with 28 additions and 21 deletions.
diff --git a/expression/date_arith.go b/expression/date_arith.go
@@ -25,24 +25,24 @@ import (
 )
 
 const (
-	add = "ADD"
-	sub = "SUB"
+	// DateAdd is to run date_add function option.
+	// See: https://dev.mysql.com/doc/refman/5.7/en/date-and-time-functions.html#function_date-add
+	DateAdd = 1
+	// DateSub is to run date_sub function option.
+	// See: https://dev.mysql.com/doc/refman/5.7/en/date-and-time-functions.html#function_date-sub
+	DateSub = 2
 )
 
 // DateArith is used for dealing with addition and substraction of time.
-// If the Op value is ADD, then do date_add function.
-// See: https://dev.mysql.com/doc/refman/5.7/en/date-and-time-functions.html#function_date-add
-// If the Op value is SUB, then do date_sub function.
-// See: https://dev.mysql.com/doc/refman/5.7/en/date-and-time-functions.html#function_date-sub
 type DateArith struct {
-	Op       string
+	Op       int
 	Unit     string
 	Date     Expression
 	Interval Expression
 }
 
 func (da *DateArith) isAdd() bool {
-	if da.Op == add {
+	if da.Op == DateAdd {
 		return true
 	}
 
@@ -67,7 +67,14 @@ func (da *DateArith) Accept(v Visitor) (Expression, error) {
 
 // String implements the Expression String interface.
 func (da *DateArith) String() string {
-	return fmt.Sprintf("DATE_%s(%s, INTERVAL %s %s)", da.Op, da.Date, da.Interval, strings.ToUpper(da.Unit))
+	var str string
+	if da.isAdd() {
+		str = "DATE_ADD"
+	} else {
+		str = "DATE_SUB"
+	}
+
+	return fmt.Sprintf("%s(%s, INTERVAL %s %s)", str, da.Date, da.Interval, strings.ToUpper(da.Unit))
 }
 
 // Eval implements the Expression Eval interface.

diff --git a/expression/date_arith_test.go b/expression/date_arith_test.go
@@ -26,7 +26,7 @@ type testDateArithSuite struct {
 func (t *testDateArithSuite) TestDateArith(c *C) {
 	input := "2011-11-11 10:10:10"
 	e := &DateArith{
-		Op:       add,
+		Op:       DateAdd,
 		Unit:     "DAY",
 		Date:     Value{Val: input},
 		Interval: Value{Val: "1"},
@@ -36,18 +36,18 @@ func (t *testDateArithSuite) TestDateArith(c *C) {
 	c.Assert(e.IsStatic(), IsTrue)
 	_, err := e.Eval(nil, nil)
 	c.Assert(err, IsNil)
-	e.Op = sub
+	e.Op = DateSub
 	c.Assert(e.String(), Equals, `DATE_SUB("2011-11-11 10:10:10", INTERVAL "1" DAY)`)
 
 	// Test null.
 	nullTbl := []struct {
-		Op       string
+		Op       int
 		Unit     string
 		Date     interface{}
 		Interval interface{}
 	}{
-		{add, "DAY", nil, "1"},
-		{add, "DAY", input, nil},
+		{DateAdd, "DAY", nil, "1"},
+		{DateAdd, "DAY", input, nil},
 	}
 	for _, t := range nullTbl {
 		e := &DateArith{
@@ -59,7 +59,7 @@ func (t *testDateArithSuite) TestDateArith(c *C) {
 		v, err := e.Eval(nil, nil)
 		c.Assert(err, IsNil)
 		c.Assert(v, IsNil)
-		e.Op = sub
+		e.Op = DateSub
 		v, err = e.Eval(nil, nil)
 		c.Assert(err, IsNil)
 		c.Assert(v, IsNil)
@@ -99,7 +99,7 @@ func (t *testDateArithSuite) TestDateArith(c *C) {
 	}
 	for _, t := range tbl {
 		e := &DateArith{
-			Op:       add,
+			Op:       DateAdd,
 			Unit:     t.Unit,
 			Date:     Value{Val: input},
 			Interval: Value{Val: t.Interval},
@@ -110,7 +110,7 @@ func (t *testDateArithSuite) TestDateArith(c *C) {
 		c.Assert(ok, IsTrue)
 		c.Assert(value.String(), Equals, t.AddExpect)
 
-		e.Op = sub
+		e.Op = DateSub
 		v, err = e.Eval(nil, nil)
 		c.Assert(err, IsNil)
 		value, ok = v.(mysql.Time)
@@ -136,7 +136,7 @@ func (t *testDateArithSuite) TestDateArith(c *C) {
 	}
 	for _, t := range errTbl {
 		e := &DateArith{
-			Op:       add,
+			Op:       DateAdd,
 			Unit:     t.Unit,
 			Date:     Value{Val: input},
 			Interval: Value{Val: t.Interval},
@@ -148,7 +148,7 @@ func (t *testDateArithSuite) TestDateArith(c *C) {
 		c.Assert(err, NotNil, Commentf("%s", v))
 
 		e = &DateArith{
-			Op:       sub,
+			Op:       DateSub,
 			Unit:     t.Unit,
 			Date:     Value{Val: input},
 			Interval: Value{Val: t.Interval},

diff --git a/parser/parser.y b/parser/parser.y
@@ -2287,7 +2287,7 @@ FunctionCallNonKeyword:
 |	"DATE_ADD" '(' Expression ',' "INTERVAL" Expression TimeUnit ')'
 	{
 		$$ = &expression.DateArith{
-			Op:"ADD",
+			Op:expression.DateAdd,
 			Unit: $7.(string), 
 			Date: $3.(expression.Expression),
 			Interval: $6.(expression.Expression),
@@ -2296,7 +2296,7 @@ FunctionCallNonKeyword:
 |	"DATE_SUB" '(' Expression ',' "INTERVAL" Expression TimeUnit ')'
 	{
 		$$ = &expression.DateArith{
-			Op:"SUB",
+			Op:expression.DateSub,
 			Unit: $7.(string),
 			Date: $3.(expression.Expression),
 			Interval: $6.(expression.Expression),