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  • Mysql 查询不重复数据

    用户表

    app表

    用户记录表

    现在要想查出用户点击的记录的列表,并且按照用户,时间排序,去掉重复的数据

    select distinct a.* from (select n.name,u.phone,n.startmoney,n.endmoney,n.type from loan_record r
    inner join loan_user u on u.id=r.uid
    inner join loan_name n on n.id=r.appid
    where r.uid in (select distinct uid from loan_record order by createdate desc) order by u.phone,r.createdate desc) as a
    where a.name='微贷'

    等价于:

    select distinct a.* from (select r.uid,n.id,n.name,n.img,n.type,n.summary,n.count,n.star from loan_name n,loan_record r
    where n.id=r.appid order by r.uid,r.createdate desc) as a;

    如果不去掉重复的,直接这样就行了

    select u.phone,n.name,n.startmoney,n.endmoney,n.type from loan_record r
    inner join loan_user u on u.id=r.uid
    inner join loan_name n on n.id=r.appid
    order by r.createdate desc;

    同时记录下之前写的代码,读者可忽略

    select * from (select * from (
    select r.uid as uid,r.cid as cid,c.rank as rank,b.bookname as bookName,b.cover as cover,r.read_date as readDate,
    b.id as bid,b.majorcate as majorCate,b.is_over as isOver
    from record r
    inner join user u on u.id=r.uid and r.uid=#{record.uid}
    inner join chapter c on c.id=r.cid
    inner join book b on b.id=c.bid
    group by r.uid,r.cid
    order by c.rank)aa ORDER BY uid asc,rank desc)cc group by bid ORDER BY readDate desc
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  • 原文地址:https://www.cnblogs.com/foreverstudy/p/10605900.html
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