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实际需求中，需要对某张表某字段里面的内容进行批量替换，普通的思考流程如下：
SELECT出来
str_replace替换
UPDATE写入
实际这样极其浪费资源以及消耗资源，MYSQL内置了一个批量替换的语法
UPDATE table SET field = replace(field,'被替换','替换成')
直接就替换了，后面也可以跟WHERE 条件语句
支持多个词同时被替换
UPDATE table SET field = replace(field,'被替换1','替换成1'),field = replace(field,'被替换2','替换成2')
很强大吧，后面那个一次性更换多个网上是没有的列子，现在记录下来bitsCN.com
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