改进多对多关联

library/think/model/relation/HasManyThrough.php

@@ -120,6 +120,18 @@ class HasManyThrough extends Relation
     public function relationCount($result, $closure)
     {}
 
+    /**
+     * 创建关联统计子查询
+     * @access public
+     * @param \Closure $closure 闭包
+     * @param string   $name    统计数据别名
+     * @return string
+     */
+    public function getRelationCountQuery($closure, &$name = null)
+    {
+        throw new Exception('relation not support: withCount');
+    }
+
     /**
      * 执行基础查询（进执行一次）
      * @access protected