子查询问题，使用“AS”和“AND”时返回SQL错误

Question

This is what im trying to run in full:

$data = $this->db->select('main.UID, main.value')
                 ->select('twitch_streams.UID AS twt')
                 ->select('(SELECT value FROM user_profile WHERE UID = main.UID AND key = "twitch" AND subkey = "update" LIMIT 1) AS check', null, FALSE)
                 ->from('user_profile AS main')
                 ->join('twitch_streams', 'twitch_streams.UID = main.UID', 'left')
                 ->where('key', 'account')
                 ->where('subkey', "TWT")
                 ->get();

With this it returns:

Error Number: 1064

You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'key = "twitch" AND subkey = "update" LIMIT 1) AS check FROM (`user_profile` AS m' at line 1

But if I shorten the SELECT to ->select('(SELECT value FROM user_profile WHERE UID = main.UID LIMIT 1)', null, FALSE) it doesn't return an error but it returns the wrong value as the key: [(SELECT value FROM user_profile WHERE UID = main.UID LIMIT 1)] => 1405874916 )

Answer 1

Key is a reserved word in mysql,wrap it with back ticks.Check is also a reserved word....

Look here and avoid them