thinkphp關聯模型 多對多 插入 怎麼使用？？？？？

$u = D('user');        $u->name = 'xiak';        $u->password = 'qqqqqq';        $u->shop = array(                'gg' => '1',            );        $u->relation(true)->add($data);

user(id, name)shop(id, name)user_shop(user_id,shop_id)

class UserModel extends RelationModel {    protected $_link = array(        'shop' => array(            'mapping_type' => self::MANY_TO_MANY,            'relation_table' => '__USER_SHOP__',                            )                       }

怎麼沒有效果啊？

sql調試是這樣的：

[user] SHOW COLUMNS FROM `tb_user` (executeTime: 0.009001s ) [user] INSERT INTO `tb_user` (`name`,`password`) VALUES ('xiak','qqqqqq') (executeTime: 0.117007s ) [shop] SHOW COLUMNS FROM `tb_shop` (executeTime: 0.013001s ) [shop] INSERT INTO tb_user_shop (user_id,shop_id) SELECT a.id,b.id FROM tb_user AS a ,tb_shop AS b where a.id =45 AND b.id IN (1) (executeTime: 0.001000s )

手冊上說 當MANY_TO_MANY時，不建議使用關聯插入。是什麼意思啊？

回複內容：

$u = D('user');        $u->name = 'xiak';        $u->password = 'qqqqqq';        $u->shop = array(                'gg' => '1',            );        $u->relation(true)->add($data);

user(id, name)shop(id, name)user_shop(user_id,shop_id)

class UserModel extends RelationModel {    protected $_link = array(        'shop' => array(            'mapping_type' => self::MANY_TO_MANY,            'relation_table' => '__USER_SHOP__',                            )                       }

怎麼沒有效果啊？

sql調試是這樣的：

[user] SHOW COLUMNS FROM `tb_user` (executeTime: 0.009001s ) [user] INSERT INTO `tb_user` (`name`,`password`) VALUES ('xiak','qqqqqq') (executeTime: 0.117007s ) [shop] SHOW COLUMNS FROM `tb_shop` (executeTime: 0.013001s ) [shop] INSERT INTO tb_user_shop (user_id,shop_id) SELECT a.id,b.id FROM tb_user AS a ,tb_shop AS b where a.id =45 AND b.id IN (1) (executeTime: 0.001000s )

手冊上說 當MANY_TO_MANY時，不建議使用關聯插入。是什麼意思啊？

難道就沒有人跟我一樣，覺得分拆SQL再加事務才是最好的方案嗎，關聯的SQL其它人看起來是不是很受罪呢

