[*] refactor: re-type Offset and Limit from struct to int

args.go

@@ -41,13 +41,9 @@ func (d *DB) handleArgs(prototype interface{}, args []interface{}) (ret *_parsed
 		case Options:
 			ret.Opt = mergeOptions(prototype, arg.(Options))
 		case Limit:
-			ret.Limit = arg.(Limit).Limit
-		case *Limit:
-			ret.Limit = arg.(*Limit).Limit
+			ret.Limit = int(arg.(Limit))
 		case Offset:
-			ret.Offset = arg.(Offset).Offset
-		case *Offset:
-			ret.Offset = arg.(*Offset).Offset
+			ret.Offset = int(arg.(Offset))
 		case Cond:
 			cond := arg.(Cond)
 			c = cond.pack(ret.FieldMap)

basic_curd_test.go

@@ -188,7 +188,7 @@ func TestQuery(t *testing.T) {
 		Condition("family_name", "<>", "Disney"),
 		Condition("die_time", "=", nil), // for MySQL NULL, should be "IS" or "IS NOT", but here er make some compatibility
 		Condition("birth_date", ">=", time.Date(1910, 1, 1, 0, 0, 0, 0, time.UTC)),
-		Offset{1}, Limit{2},
+		Offset(1), Limit(2),
 		Order{"id", "DESC"},
 	)
 	if err != nil {
@@ -231,7 +231,7 @@ func TestQuery(t *testing.T) {
 		},
 		Condition("first_name", "=", "Diane"),
 		Condition("family_name", "=", "Miller"),
-		Limit{1},
+		Limit(1),
 	)
 	if err != nil {
 		t.Errorf("Update failed: %v", err)

insert_on_duplicate_update_test.go

@@ -141,7 +141,7 @@ func TestInsertManyOnDuplicateKeyUpdate(t *testing.T) {
 
 	_, err = db.InsertManyOnDuplicateKeyUpdate(
 		ins, map[string]interface{}{
-			"f_id": Raw("= f_id"),
+			"f_id": Raw("= VALUES(`f_id`)"),
 		},
 	)
 	if err != nil {

transaction.go

@@ -0,0 +1 @@
+package mysqlx

type.go

@@ -114,11 +114,15 @@ type Options struct {
 }
 
 // Offset is for MySQL offset statement
-type Offset struct {
-	Offset int
-}
+type Offset int
 
 // Limit is for MySQL limit statement
-type Limit struct {
-	Limit int
-}
+type Limit int
+
+// Raw stores a raw MySQL query statement. In mysqlx operation, Raw type will added to sql query statement directly
+// without any escaping.
+//
+// Currently only update fields supports Raw, like:
+//
+//     map[string]interface{}{"id": mysqlx.Raw("= id")}
+type Raw string