tp3.2 and or的复合查询

$where['user_id']  = $user_id;
$where['buy_id']  = $user_id;
$where['_logic'] = 'or';
$map['_complex'] = $where;
$map['trade_type'] ='1';
$map['status']  = array('gt',0);
$marketdata = M('Market')->where($map)->select();
echo M()->_sql();

原生语句就是 
SELECT * FROM `erj_market` WHERE ( `user_id` = '13' OR `buy_id` = '13' ) AND `trade_type` = 1 AND `status` > 0