diff --git a/dbpool.go b/dbpool.go
index e989032..74ceb62 100644
--- a/dbpool.go
+++ b/dbpool.go
@@ -99,7 +99,6 @@ func (this *dbPool) SelectOne(
 func (this *dbPool) OrmSelectOne(
 	dataSource string,
 	tblName string,
-	fields []string,
 	whereKv [][]string,
 	cb QueryOneCb) {
 	params := []string{}
@@ -193,14 +192,15 @@ func (this *dbPool) borrowConn(name string) *dataSource {
 	for tryCount < 5 {
 		{
 			this.lock.Lock()
-			defer this.lock.Unlock()
 			if head, ok := this.dataSourceHash[name]; ok {
 				if !head.Empty() {
 					next := head.Next()
 					next.Del()
+					this.lock.Unlock()
 					return next.GetData().(*dataSource)
 				}
 			}
+			this.lock.Unlock()
 		}
 		time.Sleep(time.Second * 1)
 		tryCount++