SQL分组去重并合并多条记录

举例说明

一，网友需要如下的效果：

       

 

其实，这个需求依然可以我上篇的方法进行解答，但为了实现分组，需要distinct group1，同时，为了根据key1,key2,key3是否相同进行分组，所以要用where进行连接。

语法格式：select .....from t1 where key1=a.key1 and key2=a.key2... for xml path('')

二，进入正题，代码如下：

 select distinct group1,key1,key2,key3,
(select concat1+',' from concat where group1=a.group1 and key1=a.key1 and key2=a.key2 and key3=a.key3 for XML PATH('') ) as concat1,
(select concat2+',' from concat where group1=a.group1 and key1=a.key1 and key2=a.key2 and key3=a.key3 for XML PATH('') ) as concat2,
(select concat3+',' from concat where group1=a.group1 and key1=a.key1 and key2=a.key2 and key3=a.key3 for XML PATH('') ) as concat3
 from concat a

 

三、效果如下：