diff --git a/session_raw.go b/session_raw.go
index acb106a5..0d20dd60 100644
--- a/session_raw.go
+++ b/session_raw.go
@@ -33,7 +33,7 @@ func (session *Session) queryRows(sqlStr string, args ...interface{}) (*core.Row
 
 	if session.isAutoCommit {
 		var db *core.DB
-		if session.sessionType == groupSession && strings.EqualFold(sqlStr[:6], "select") {
+		if session.sessionType == groupSession && strings.EqualFold(strings.TrimSpace(sqlStr)[:6], "select") {
 			db = session.engine.engineGroup.Slave().DB()
 		} else {
 			db = session.DB()