今天在工作的过程中碰到一个问题,要把数据库中某个列的所有值中含有"shop.xxxx.net"的字符更换成"www.nowamagic.net",本来可以写个脚本,把所有的值都取出再用php进行处理,但是那样就效率非常低了,想到看试下能不能直接在MySQL中用SQL语句直接来处理,经
今天在工作的过程中碰到一个问题,要把数据库中某个列的所有值中含有"shop.xxxx.net"的字符更换成"www.nowamagic.net",本来可以写个脚本,把所有的值都取出再用php进行处理,但是那样就效率非常低了,想到看试下能不能直接在MySQL中用SQL语句直接来处理,经过一番搜索,终于找到解决方案,其实最重要的是mysql的replace函数,关于这个函数的介绍,我在MySQL手册中是没看懂,不过能实现我想要的功能就行。
下面就是对这个函数的简要介绍以及范例。
比如你要将 表 tb1里面的 f1字段的abc替换为def:
UPDATE tb1 SET f1=REPLACE(f1, 'abc', 'def'); REPLACE(str,from_str,to_str)
在字符串 str 中所有出现的字符串 from_str 均被 to_str替换,然后返回这个字符串:
mysql> SELECT REPLACE('www.mysql.com', 'w', 'Ww'); -> 'WwWwWw.mysql.com'
这个函数是多字节安全的。
示例:
UPDATE `dede_addonarticle` SET body = REPLACE ( body,'</td>'," ); UPDATE `dede_addonarticle` SET body = REPLACE ( body,'</tr>'," ); UPDATE `dede_addonarticle` SET body = REPLACE ( body,'<tr>'," ); UPDATE `dede_archives` SET title= REPLACE ( title,'简明现代魔法 – '," ); UPDATE `dede_addonarticle` SET body = REPLACE ( body,'../../../../../../','http://special.dayoo.com/meal/' );
mysql replace
用法1.replace intoreplace into table (id,name) values('1','aa'),('2','bb')
此语句的作用是向表table中插入两条记录。
2.replace(object, search,replace)
把object中出现search的全部替换为replaceselect replace('www.163.com','w','Ww')—>WwW wWw.163.com
例:把表table中的name字段中的 aa替换为bbupdate table set name=replace(name,'aa','bb')
Sql Server 中 text或ntext 字段内容替换
刚开始,Update AA 表 Set xx字段=Replace(xx字段,"要替换的","特定串") ,出现错误:函数 replace 的参数 1 的数据类型 ntext 无效。Update article set heading=Replace(convert(nvarchar(4000),heading),'<script></script>','')
update 表名 set text类型字段名=replace(convert(varchar(8000),text类型字段名),'要替换的字符','替换成的值')
varchar和nvarchar类型是支持replace,所以如果你的text/ntext不超过8000/4000可以先转换成前面两种类型再使用replace。
update 表名 set text类型字段名=replace(convert(varchar(8000),text类型字段名),'要替换的字符','替换成的值')
update 表名 set ntext类型字段名=replace(convert(nvarchar(4000),ntext类型字段名),'要替换的字符','替换成的值')
如果text/ntext超过8000/4000,看如下例子:
declare @pos int declare @len int declare @str nvarchar(4000) declare @des nvarchar(4000) declare @count int set @des ='<requested_amount+1>'--要替换成的值 set @len=len(@des) set @str= '<requested_amount>'--要替换的字符 set @count=0--统计次数. WHILE 1=1 BEGIN select @pos=patINDEX('%'+@des+'%',propxmldata) - 1 from 表名 where 条件 IF @pos>=0 begin DECLARE @ptrval binary(16) SELECT @ptrval = TEXTPTR(字段名) from 表名 where 条件 UPDATETEXT 表名.字段名 @ptrval @pos @len @str set @count=@count+1 end ELSE break; END select @count

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