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分类: Mysql/postgreSQL

2014-01-14 17:05:35

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

点击(此处)折叠或打开

  1. [oldboy_c64 ~]# mysql --help|grep dummy
  2. -U, --i-am-a-dummy Synonym for option --safe-updates, -U.
  3. 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

点击(此处)折叠或打开

  1. [oldboy_c64 ~]# mysql -uroot -poldboy123 -S /data/3306/mysql.sock -U
  2. Welcome to the MySQL monitor. Commands end with ; or \g.
  3. Your MySQL connection id is 14
  4. Server version: 5.5.32-log MySQL Community Server (GPL)
  5. Copyright (c) 2000, 2013, Oracle and/or its affiliates. All rights reserved.
  6. Oracle is a registered trademark of Oracle Corporation and/or its
  7. affiliates. Other names may be trademarks of their respective
  8. owners.
  9. Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
  10. mysql> delete from oldboy.student;
  11. ERROR 1175 (HY000): You are using safe update mode and you tried to update a table without a WHERE that uses a KEY column
  12. mysql> quit
  13. 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

点击(此处)折叠或打开

  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 table without a WHERE that uses a KEY column
  9. mysql> delete from oldboy.student where Sno=5;
  10. Query OK, 1 row affected (0.02 sec)
  11. mysql> quit
  12. Bye
  13. [oldboy_c64 ~]# echo "alias mysql='mysql -U'" >>/etc/profile
  14. [oldboy_c64 ~]# . /etc/profile
  15. [oldboy_c64 ~]# tail -1 /etc/profile
  16. 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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