以上是两张数据表，user表和friends表，
<?php
namespace Home\Model;
use Think\Model\RelationModel;
class UserModel extends RelationModel{
protected $_link=array(
'friends'=>array(
'mapping_type'=> self::HAS_MANY,
'class_name'=>'friends',
'foreign_key'=>'userid',
),
);
}
以上是模型类
<?php
namespace Home\Controller;
use Think\Controller;
class TestController extends Controller {
public function index(){
$user=D('user');
$row=$user->relation(true)->where('Uid=7')->select();
print_r($row);
}
}
以上上控制器代码
Array( [0] => Array ( [uid] => 7 [user_name] => 44444 [nickname] => [password] => 44444 [tel] => [grade] => 1 [empirical] => 0 [haveprice] => 0.00 [friends] => Array ( ) ))
以上是打印的结果，为什么始终friends中是空数据啊，求大神指点一下，难道是