改进Relation类

library/think/model/Relation.php

@@ -72,6 +72,7 @@ class Relation
         $relation   = $this->parent->$name();
         $foreignKey = $this->foreignKey;
         $localKey   = $this->localKey;
+        if ($relation instanceof Relation) {
             // 判断关联类型执行查询
             switch ($this->type) {
                 case self::HAS_ONE:
@@ -107,6 +108,9 @@ class Relation
                     $result = $relation;
             }
             return $result;
+        } else {
+            return $relation;
+        }
     }
 
     /**