• sql语句查询结果合并union all用法


    整理别人的sql

    大概的思想是用union 和union all

    --合并重复行
    select * from A
    union
    select * from B


    --不合并重复行
    select * from A
    union all
    select * from B


    按某个字段排序
    --合并重复行
    select *
    from (
    select * from A
    union
    select * from B) AS T
    order by 字段名

    --不合并重复行
    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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  • 原文地址:https://www.cnblogs.com/MaxElephant/p/10281286.html
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