ThinkPHP 中 where条件 or,and 同时使用

1、where 的用法，参考一下：https://www.kancloud.cn/manual/thinkphp5/135182

2、where条件 or,and 同时使用 。一定要打括号。不然执行会出错。

('a'=1 and 'b'=2) or ('c'=3 and 'd'=4) and 'e'=5

$where_1['a'] = 1;
$where_1['b'] = 2;
$where_2['c'] = 3;
$where_2['d'] = 4;
$where_main['_complex'] = array(
    $where_1,
    $where_2,
    '_logic' => 'or'
);
$where_main['e'] = 5;
$this->user->where($where_main)->select();

SELECT * FROM `ecs_order_info` WHERE ( ( `order_status` = 5 AND `shipping_status` = 2 ) OR `order_status` = 6 ) AND `user_id` = 1

怎么检测我们写的sql语句没有错呢？执行下面这条语句就可以了，只会翻译成sql语句，不会执行。

echo $order->where($final)->fetchSql(true)->select();