sql语句查询结果合并union all用法

    技术2022-05-11  70

    整理别人的sql

    大概的思想是用union 和union all 

    --合并重复行select * from Aunion select * from B

    --不合并重复行select * from Aunion allselect * from B

    按某个字段排序--合并重复行select *from (select * from Aunion select * from B) AS Torder by 字段名

    --不合并重复行select *from (select * from Aunion allselect * from B) AS Torder by 字段名

    //sql server版Select * From (select top 2 id,adddate,title,url from bArticle where ClassId='1' order by adddate desc) AUnion AllSelect * From (select top 2 id,adddate,title,url from bArticle where ClassId='2' order by adddate desc) BUnion AllSelect * From (select top 2 id,adddate,title,url from bArticle where ClassId='3' order by adddate desc) CUnion AllSelect * From (select top 2 id,adddate,title,url from bArticle where ClassId='4' order by adddate desc) D

    //mysql版Select * From (select id,adddate,title,url from bArticle where ClassId='1' order by adddate desc limit 0,2) AUnion AllSelect * From (select id,adddate,title,url from bArticle where ClassId='2' order by adddate desc limit 0,2) BUnion AllSelect * From (select id,adddate,title,url from bArticle where ClassId='3' order by adddate desc limit 0,2) CUnion AllSelect * From (select id,adddate,title,url from bArticle where ClassId='4' order by adddate desc limit 0,2) D

     


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