feat: add order by asc expr (#1034)

* feat: add order by asc expr

* feat: add order by asc expr

Author: dino-ma

do_test.go

@@ -162,6 +162,18 @@ func TestDO_methods(t *testing.T) {
 			Expr:   u.Order(u.ID.Desc()).Order(u.Age),
 			Result: "ORDER BY `id` DESC,`age`",
 		},
+		{
+			Expr:   u.Order(u.ID.Asc()),
+			Result: "ORDER BY `id` ASC",
+		},
+		{
+			Expr:   u.Order(u.ID.Asc(), u.Age),
+			Result: "ORDER BY `id` ASC,`age`",
+		},
+		{
+			Expr:   u.Order(u.ID.Asc()).Order(u.Age),
+			Result: "ORDER BY `id` ASC,`age`",
+		},
 		{
 			Expr:   u.Clauses(hints.New("hint")).Select(),
 			Result: "SELECT /*+ hint */ *",

field/expr.go

@@ -48,6 +48,7 @@ type Expr interface {
 type OrderExpr interface {
 	Expr
 	Desc() Expr
+	ASC() Expr
 }
 
 type expression interface{}
@@ -274,10 +275,16 @@ func (e expr) As(alias string) Expr {
 	return e
 }
 
+// Desc sort by desc
 func (e expr) Desc() Expr {
 	return e.setE(clause.Expr{SQL: "? DESC", Vars: []interface{}{e.RawExpr()}})
 }
 
+// Asc sort by asc
+func (e expr) Asc() Expr {
+	return e.setE(clause.Expr{SQL: "? ASC", Vars: []interface{}{e.RawExpr()}})
+}
+
 // ======================== general experssion ========================
 func (e expr) value(value interface{}) AssignExpr {
 	return e.setE(clause.Eq{Column: e.col.Name, Value: value})