完善数据库驱动

library/think/db/builder/Oracle.php

@@ -41,11 +41,11 @@ class Oracle extends Builder
         }
         return $limitStr ? ' WHERE ' . $limitStr : '';
     }
+
     /**
      * 设置锁机制
      * @access protected
      * @param bool|false $lock
-     *
      * @return string
      */
     protected function parseLock($lock = false)

library/think/db/builder/Sqlsrv.php

@@ -58,11 +58,11 @@ class Sqlsrv extends Builder
 
     /**
      * limit
-     * @access public
+     * @access protected
      * @param mixed $limit
      * @return string
      */
-    public function parseLimit($limit)
+    protected function parseLimit($limit)
     {
         if (empty($limit)) {
             return '';