小编Ces*_*pez的帖子

我正在处理这张表：

mysql> describe dispositivos;
+-----------+-------------+------+-----+---------+-------+
| Field     | Type        | Null | Key | Default | Extra |
+-----------+-------------+------+-----+---------+-------+
| sn        | varchar(25) | NO   | PRI | NULL    |       |
| device_id | varchar(25) | YES  |     | NULL    |       |
| ip_adress | varchar(25) | YES  |     | NULL    |       |
+-----------+-------------+------+-----+---------+-------+
3 rows in set (0.00 sec)

我注意到当我输入这样的查询时：

mysql> select * from dispositivos WHERE sn = "SAL1027TVGH";
+-------------+---------------+------------------+
| sn          | device_id     | ip_adress        |
+-------------+---------------+------------------+
| …