如何使用RegEx在c＃中的字符串中查找最后一次出现的'，'

Question

如何使用RegEx在c＃中的字符串中查找最后一次出现的'，'

我试过下面的代码

string ss = Regex.Replace(strQuery, @"/\,(?<firstMatch>.*)=case(?<secondMatch>.*end\b)", @" case ${secondMatch} ""${firstMatch}"" ", RegexOptions.IgnoreCase);

输入

 SELECT  * FROM (select  TOP 5 ROW_NUMBER() OVER (ORDER BY Region_desc) as ROW_NUM,* from (select *, ROW_NUMBER() over (order by Region_desc desc) as gridviewcount from( SELECT BO_REGION_MASTER.Region_ID,BO_REGION_MASTER.Region_CODE,BO_REGION_MASTER.Region_DESC,STATUS=CASE WHEN BO_REGION_MASTER.STATUS='A' THEN 'ACTIVE' WHEN BO_REGION_MASTER.STATUS='I' THEN 'INACTIVE' ELSE '' END,

我正在输出

SELECT * FROM (select TOP 5 ROW_NUMBER() OVER (ORDER BY Region_desc) as ROW_NUM,* from (select *, ROW_NUMBER() over (order by Region_desc desc) as gridviewcount from( SELECT BO_REGION_MASTER.Region_ID,BO_REGION_MASTER.Region_CODE,BO_REGION_MASTER.Region_DESC,STATUS=CASE WHEN BO_REGION_MASTER.STATUS='A' THEN 'ACTIVE' WHEN BO_REGION_MASTER.STATUS='I' THEN 'INACTIVE' ELSE '' END,

但我需要如下输出

 SELECT  * FROM (select  TOP 5 ROW_NUMBER() OVER (ORDER BY Region_desc) as ROW_NUM,* from (select *, ROW_NUMBER() over (order by Region_desc desc) as gridviewcount from( SELECT BO_REGION_MASTER.Region_ID,BO_REGION_MASTER.Region_CODE,BO_REGION_MASTER.Region_DESC,CASE WHEN BO_REGION_MASTER.STATUS='A' THEN 'ACTIVE' WHEN BO_REGION_MASTER.STATUS='I' THEN 'INACTIVE' ELSE '' END "STATUS",

Answer 1

使用以下正则表达式，然后将匹配项替换为$2 $1,

(?i).*,([^=]*)=(CASE.*),

要么

(?i).*,([^=]*)=(CASE.*end)\b

如果要进行不区分大小写的匹配，请在开头添加不区分大小写的修饰符(?i) 。

DEMO

string ss = Regex.Replace(strQuery, @".*,([^=]*)=(CASE.*end)\b",  "$2 $1", RegexOptions.IgnoreCase);

DEMO

更新：

(?i)(.*,)([^=]*)=(CASE.*end)\b

替换字符串：

$1$3 "$2"

DEMO