MySQL 删除字段

Question

为什么我不能从 MySQL 数据库中删除字段¿？

mysql> describe Clients;

+-------------+--------------+------+-----+---------+----------------+
| Field       | Type         | Null | Key | Default | Extra          |
+-------------+--------------+------+-----+---------+----------------+
| id          | int(11)      | NO   | PRI | NULL    | auto_increment |
| name        | varchar(255) | NO   |     | NULL    |                |
| shurname    | varchar(255) | NO   |     | NULL    |                |
| email       | varchar(255) | NO   |     | NULL    |                |
| password    | varchar(255) | NO   |     | NULL    |                |
| userId      | int(11)      | NO   |     | NULL    |                |
| userMessage | varchar(255) | YES  |     | NULL    |                |
| userName    | varchar(255) | YES  |     | NULL    |                |
| pwd         | varchar(255) | YES  |     | NULL    |                |
| surname     | varchar(255) | YES  |     | NULL    |                |
+-------------+--------------+------+-----+---------+----------------+
10 rows in set (0.00 sec)

mysql> ALTER TABLE Clients DROP userId;
^CCtrl-C -- sending "KILL QUERY 104" to server ...
Ctrl-C -- query aborted.
ERROR 1317 (70100): Query execution was interrupted
mysql> ALTER TABLE Clients DROP userMessage;

它并没有完成，它卡住并且不删除.... 我想删除 userId、userMessage、userName、pwd 和 surname。

Answer 1

如果您首先删除自动增量并删除主键，您应该能够删除该字段。也许即使只是删除自动增量也会这样做，但不确定。无论如何，其他字段应该删除。

Answer 2

我什至不能删除作为 root 的表：

mysql> show tables;
+-------------------------+
| Tables_in_Hoteles_Compu |
+-------------------------+
| Clients                 |
| Coords                  |
| Hotels                  |
| Rate                    |
| Regions                 |
+-------------------------+
5 rows in set (0.00 sec)

mysql> drop table Coords;
Query OK, 0 rows affected (0.04 sec)

mysql> drop table Clients;