三个表用户表:
table 用户
字段 userid文章表:
table log
字段:logid,userid评论表:
table review
字段 reviewid,logid,userid================
列出有某用户评论的文章,并以文章最新评论排序。就象这里“我参与的帖子”功能,一条sql怎以写?
table 用户
字段 userid文章表:
table log
字段:logid,userid评论表:
table review
字段 reviewid,logid,userid================
列出有某用户评论的文章,并以文章最新评论排序。就象这里“我参与的帖子”功能,一条sql怎以写?
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set @userid='xxx'select
t.*
from
log t
where
exists(select 1 from review where logid=t.logid and userid=@userid)
order by
(select max(reviewid) from review where logid=t.logid) desc
sql输出:
"select A.LogKey,A.LogTitle,B.UserName from logs AS A left join users AS B on A.LogUserId=B.UserKey exists(select 1 from reviews where reviewLogId=A.LogKey and reviewUserId=2944) order by (select max(reviewKey) AS reviewKey from reviews where reviewLogId=A.LogKey) desc limit 20;"错误显示:
You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'exists(select 1 from reviews where reviewLogId=A.LogKey and reviewU' at line 4
A.LogKey,
A.LogTitle,
B.UserName
from
logs AS A
left join
users AS B
on
A.LogUserId=B.UserKey
where
exists(select 1 from reviews where reviewLogId=A.LogKey and reviewUserId=2944)
order by
(select max(reviewKey) AS reviewKey from reviews where reviewLogId=A.LogKey) desc limit 20
select logid from review where userid='wangsan' order by reviewid desc这样?
select max(reviewid),logid from (
select * from review where userid=xxx
) t
group by logid
set @userid='xxx';
select
t.*
from
log t
where
exists(select 1 from review where logid=t.logid and userid=@userid)
order by
(select max(reviewid) from review where logid=t.logid) desc
去执行一下吧!
好象mysql不支持這句exists(select 1 from review where logid=t.logid and userid=@userid)
distinct
A.LogKey,
A.LogTitle,
B.UserName
from
logs AS A
left join
users AS B
on
A.LogUserId=B.UserKey
left join
reviews AS C
on
C.reviewLogId=A.LogKey
where
C.reviewUserId=2944
order by
(select max(reviewKey) AS reviewKey from reviews where reviewLogId=A.LogKey) desc limit 20