diff --git a/database.go b/database.go
index 364175f..a9a8c45 100644
--- a/database.go
+++ b/database.go
@@ -30,3 +30,8 @@ const (
 	WhereOperateLike     = "like"      // like
 	WhereOperateNotLike  = "not_like"  // not like
 )
+
+const (
+	OrderRuleAsc  = "asc"  // 升序
+	OrderRuleDesc = "desc" // 降序
+)