sql 查询结果合并union all用法_数据库技巧

复制代码 代码如下:–合同等对待复行 select *
from A union select * from B –不合比量齐观复行 select * from A union all
select * from B 按某些字段排序 –合天公地道复行 select * from ( select *
from A union select * from B卡塔尔国 AS T order by 字段名 –不统生龙活虎重复行
select * from ( select * from A union all select * from B) AS T order
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) A Union All Select * From ( select top 2 id,adddate,title,url
from bArticle where ClassId=2 order by adddate desc) B Union All Select
* From ( select top 2 id,adddate,title,url from bArticle where
ClassId=3 order by adddate desc) C Union All Select * 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) A Union All
Select * From ( select id,adddate,title,url from bArticle where
ClassId=2 order by adddate desc limit 0,2) B Union All Select * From (
select id,adddate,title,url from bArticle where ClassId=3 order by
adddate desc limit 0,2) C Union All Select * From ( select
id,adddate,title,url from bArticle where ClassId=4 order by adddate desc
limit 0,2) D

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