防止人为误操作MySQL数据库技巧一例_MySQL

（本题来自老男孩培训内部学生问题，属于数据库安全技巧）

在若干年前，老男孩亲自遇到一个“命案”，老大登录数据库update一个记录，结果忘了加where，于是悲剧发生了，这使得我对MySQL的增量恢复熟练度远超过其他的知识点，同时也很在意对内的数据库安全，并且每次讲课讲到此处，都会给学生讲这个领导的故事。

1、mysql帮助说明

[oldboy_c64 ~]# mysql --help|grep dummy       
 -U, --i-am-a-dummy Synonym for option --safe-updates, -U. 
i-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

2、指定-U登录测试

[oldboy_c64 ~]# mysql -uroot -poldboy123 -S /data/3306/mysql.sock -U 
Welcome to the MySQL monitor. Commands end with ; or \g. 
Your MySQL connection id is 14 
Server version: 5.5.32-log MySQL Community Server (GPL) 
Copyright (c) 2000, 2013, Oracle and/or its affiliates. All rights reserved. 
Oracle is a registered trademark of Oracle Corporation and/or its 
affiliates. Other names may be trademarks of their respective 
owners. 
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement. 
mysql> delete from oldboy.student; 
ERROR 1175 (HY000): You are using safe update mode and you tried to update a table without a WHERE that uses a KEY column 
mysql> quit 
Bye 

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

[oldboy_c64 ~]# alias mysql='mysql -U' 
[oldboy_c64 ~]# mysql -uroot -poldboy123 -S /data/3306/mysql.sock 
Welcome to the MySQL monitor. Commands end with ; or \g. 
Your MySQL connection id is 15 
Server version: 5.5.32-log MySQL Community Server (GPL) 
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement. 
mysql> delete from oldboy.student; 
ERROR 1175 (HY000): You are using safe update mode and you tried to update a table without a WHERE that uses a KEY column 
mysql> delete from oldboy.student where Sno=5; 
Query OK, 1 row affected (0.02 sec) 
mysql> quit 
Bye 
[oldboy_c64 ~]# echo "alias mysql='mysql -U'" >>/etc/profile 
[oldboy_c64 ~]# . /etc/profile 
[oldboy_c64 ~]# tail -1 /etc/profile 
alias mysql='mysql -U' 

结论：

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程序拒绝执行