发布于 2016-03-14 00:57:26 | 130 次阅读 | 评论: 0 | 来源: 网友投递

这里有新鲜出炉的Mysql教程,程序狗速度看过来!

Mysql关系型数据库管理系统

MySQL是一个开放源码的小型关联式数据库管理系统,开发者为瑞典MySQL AB公司。MySQL被广泛地应用在Internet上的中小型网站中。由于其体积小、速度快、总体拥有成本低,尤其是开放源码这一特点,许多中小型网站为了降低网站总体拥有成本而选择了MySQL作为网站数据库。


这篇文章主要介绍了MySQL数据库防止人为误操作的方法,需要的朋友可以参考下

有不少开发人员在操作MySQL数据库的时候都遇到过误操作的情况,例如更新数据库的时候update语句忘记加上where条件,就会造成极为悲剧的结果。本文就针对防止MySQL数据库误操作的方法做出如下详解:

1、mysql帮助说明


# 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


# 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:此处不加条件无法删除,目的达到。

3、做成别名防止DBA误操作


# alias mysql='mysql -U' 
# 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 
# echo "alias mysql='mysql -U'" >>/etc/profile 
# . /etc/profile 
# 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



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