orm: support filter raw sql

orm/orm_conds.go

@@ -31,6 +31,8 @@ type condValue struct {
 	isOr   bool
 	isNot  bool
 	isCond bool
+	isRaw  bool
+	sql    string
 }
 
 // Condition struct.
@@ -45,6 +47,15 @@ func NewCondition() *Condition {
 	return c
 }
 
+// Raw add raw sql to condition
+func (c Condition) Raw(expr string, sql string) *Condition {
+	if len(sql) == 0 {
+		panic(fmt.Errorf("<Condition.Raw> sql cannot empty"))
+	}
+	c.params = append(c.params, condValue{exprs: strings.Split(expr, ExprSep), sql: sql, isRaw: true})
+	return &c
+}
+
 // And add expression to condition
 func (c Condition) And(expr string, args ...interface{}) *Condition {
 	if expr == "" || len(args) == 0 {