mysql 帮助说明

1[oldboy_c64 ~]# mysql --help|grep dummy

2 -U, --i-am-a-dummy Synonym for option --safe-updates, -U.

3i-am-a-dummy       FALSE

在 mysql 命令加上选项-U 后，当发出没有 WHERE 或 LIMIT 关键字的 UPDATE 或 DELETE 时，

mysql 程序就会拒绝执行

[oldboy_c64 ~]# mysql -uroot -poldboy123 -S /data/3306/mysql.sock –U

1

Welcome to the MySQL monitor. Commands end with ; or \g.

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Your MySQL connection id is 14

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Server version: 5.5.32-log MySQL Community Server (GPL)

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Copyright (c) 2000, 2013, Oracle and/or its affiliates. All rights reserved.

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Oracle is a registered trademark of Oracle Corporation and/or its

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affiliates. Other names may be trademarks of their respective

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owners.

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Type 'help;' or '\h' for help. Type '\c' to
clear the current input statement.

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mysql> delete from oldboy.student;

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ERROR 1175 (HY000): You are using safe update mode and you tried to update a

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table without a
WHERE that uses a KEY column

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mysql> quit

13

Bye

103

提示：不加条件无法删除，目的达到。

3、做成别名防止老大和 DBA 误操作

1  [oldboy_c64 ~]# alias mysql='mysql -U'

2  [oldboy_c64 ~]# mysql -uroot -poldboy123 -S /data/3306/mysql.sock

3  Welcome to the MySQL monitor. Commands end with ; or \g.

4  Your MySQL connection id is 15

5  Server version: 5.5.32-log MySQL Community Server (GPL)

6  Type 'help;' or '\h' for help. Type '\c' to
clear the current input statement.

7  mysql> delete from oldboy.student;

8  ERROR 1175 (HY000): You are using safe update mode and you tried to update a

9  table without a WHERE that uses a
KEY column

10mysql> delete from oldboy.student where Sno=5;

11Query OK, 1 row affected (0.02 sec)

12mysql> quit

104