这篇文章给大家介绍如何进行MYSQL特殊字符的处理,内容非常详细,感兴趣的小伙伴们可以参考借鉴,希望对大家能有所帮助。
单引号,以及行尾的斜杠引起的困惑:
这一次的问题,我们直接从实际的工作中说起:
工作内容简介: 有一批用户ID存在文件里,需要从数据库里删除?
做这个事情,可能有很多的方法:
1, 把ID导入到数据库中,用SQL直接做表关联去删除 ;
2, 用SHELL(或其他语言)写个小程序,根据文件里的ID做一个FOR 循环,然后在MYSQL中去删除 ;
3, 用sed直接把ID转成delete语句,完了直接运行即可;
[@more@]
由于数据量较大(1.6亿),显然,我会用偷懒以及简单的方法3 :
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[root@im_ctuallot1 tmp]# cat loginid.txt
xouqun76818
ogku15mtb7c
jinlongkaikai@163.com
曾朴绍283902
轻舞飞扬061129付了
[root@im_ctuallot1 tmp]# sed -e "s/^/delete from ctulog.db_allot_center_64 where long_id='/g" -e "s/$/';/g" loginid.txt > loginid.sql
[root@im_ctuallot1 tmp]# cat loginid.sql
delete from ctulog.db_allot_center_64 where long_id='xouqun76818';
delete from ctulog.db_allot_center_64 where long_id='ogku15mtb7c';
delete from ctulog.db_allot_center_64 where long_id='jinlongkaikai@163.com';
delete from ctulog.db_allot_center_64 where long_id='曾朴绍283902';
delete from ctulog.db_allot_center_64 where long_id='轻舞飞扬061129付了';
mysql -uroot -h227.0.0.1 --default-character-set=latin1 --force ctulogdb < loginid.sql
--force 是防止某个SQL出现错误,而导致整个任务终止;
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搞定。
这看似非常简单的方法,也暴露出很多的问题,结果1.6行数据只成功删除了3300W,任务失败;
其实是我把这个任务想得太简单了: 在用户ID中存在任何可能的字符 ,如:
bao'pijkl
tingting831118
注意,在用户ID中有" ' ", 在行末尾有:" ";
我们把这样的语句渗杂到其他ID中,我们看会有怎么的效果;
[root@im_ctuallot1 tmp]# cat loginid.txt
xouqun76818
bao'pijkl
ogku15mtb7c
jinlongkaikai@163.com
曾朴绍283902
tingting831118
轻舞飞扬061129付了
[root@im_ctuallot1 tmp]# sed -e "s/^/delete from ctulog.db_allot_center_64 where long_id='/g" -e "s/$/';/g" loginid.txt > loginid.sql
[root@im_ctuallot1 tmp]# cat loginid.sql
delete from ctulog.db_allot_center_64 where long_id='xouqun76818';
delete from ctulog.db_allot_center_64 where long_id='bao'pijkl';
delete from ctulog.db_allot_center_64 where long_id='ogku15mtb7c';
delete from ctulog.db_allot_center_64 where long_id='jinlongkaikai@163.com';
delete from ctulog.db_allot_center_64 where long_id='曾朴绍283902';
delete from ctulog.db_allot_center_64 where long_id='tingting831118';
delete from ctulog.db_allot_center_64 where long_id='轻舞飞扬061129付了';
[root@im_ctuallot1 tmp]# mysql -uroot -h227.0.0.1 --default-character-set=latin1 --force ctulog < loginid.sql
ERROR at line 2: Unknown command '''.
ERROR 1064 (42000) at line 2: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'pijkl';
delete from ctulog.db_allot_center_64 where long_id='ogku15mtb7c';
delet' at line 1
会出现一堆这样的错误;
如果你手动把以上SQL贴到MYSQL中去执行:
root@127.0.0.1 : ctulog 15:59:04>
root@127.0.0.1 : ctulog 15:59:04> delete from ctulog.db_allot_center_64 where long_id='xouqun76818';
Query OK, 0 rows affected (0.00 sec)
root@127.0.0.1 : ctulog 15:59:05> delete from ctulog.db_allot_center_64 where long_id='bao'pijkl';
'> delete from ctulog.db_allot_center_64 where long_id='ogku15mtb7c';
'> delete from ctulog.db_allot_center_64 where long_id='jinlongkaikai@163.com';
'> delete from ctulog.db_allot_center_64 where long_id='曾朴绍283902';
'> delete from ctulog.db_allot_center_64 where long_id='tingting831118';
ERROR:
Unknown command '''.
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'pijkl';
delete from ctulog.db_allot_center_64 where long_id='ogku15mtb7c';
delet' at line 1
root@127.0.0.1 : ctulog 15:59:05> delete from ctulog.db_allot_center_64 where long_id='轻舞飞扬061129付了';
Query OK, 0 rows affected (0.00 sec)
root@127.0.0.1 : ctulog 15:59:10>
只有第一条,最后一条执行成功了;
到这里我想大家应该明白了,
最关键的是单引号的不匹配导致MYSQL不能正确认识完整的SQL;
注意,在用户ID中,出现 单个单引号,或以""结束,都会有这个问题;
问题找到了,其实解决很简单,就是先把用户ID中的单引号和"$"作一个转换:
[root@im_ctuallot1 tmp]# cat loginid.txt
xouqun76818
bao'pijkl
ogku15mtb7c
jinlongkaikai@163.com
曾朴绍283902
tingting831118
轻舞飞扬061129付了
[root@im_ctuallot1 tmp]# sed -e "s///g" -e "s/'/'/g" -e "s/^/delete from ctulog.db_allot_center_64 where long_id='/g" -e "s/$/';/g" loginid.txt > loginid.sql
[root@im_ctuallot1 tmp]# cat loginid.sql
delete from ctulog.db_allot_center_64 where long_id='xouqun76818';
delete from ctulog.db_allot_center_64 where long_id='bao'pijkl';
delete from ctulog.db_allot_center_64 where long_id='ogku15mtb7c';
delete from ctulog.db_allot_center_64 where long_id='jinlongkaikai@163.com';
delete from ctulog.db_allot_center_64 where long_id='曾朴绍283902';
delete from ctulog.db_allot_center_64 where long_id='tingting831118';
delete from ctulog.db_allot_center_64 where long_id='轻舞飞扬061129付了';
[root@im_ctuallot1 tmp]#
是这样的SQL执行就不会有任何问题。
就这么简单的问题,耗了5个小时,还是SHARE一下以免大家在这里浪费时间。
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