按日期顺序不返回结果进行分组

时间:2014-08-08 04:52:21

标签: php mysql codeigniter sql-order-by greatest-n-per-group

在我的项目中,当用户观看视频时,它将被插入到用于存储已观看电影详细信息的表格中。

我正在使用以下查询来获取当前用户按最新记录顺序查看的电影。如果用户多次观看过视频,则应仅返回其中的最新记录。

我正在使用以下查询。

SELECT vm.watched_on,vm.movie_id,cp.channel_id,
v.title, v.videothumbnail, v.views, v.likes, v.length, v.videoid,
cp.title as videotitle, cv.thumbnail,cv.views as cvviews,cv.likes as cvlikes, cv.id,cp.starttime,cp.endtime,vm.videotype
FROM viewedmovies as vm
LEFT JOIN video as v
ON (vm.movie_id=v.videoid AND vm.user_id=1 AND vm.videotype=1 and v.permission!=-1)
LEFT JOIN channel_videos as cv
ON (vm.movie_id=cv.id AND vm.user_id=1 AND (vm.videotype=0 or vm.videotype=2))
LEFT JOIN channel_programmes as cp
ON (vm.movie_id=cp.programme_source AND (vm.videotype=0 or vm.videotype=2) AND cp.status!=-1) 
where vm.user_id=1 GROUP BY vm.user_id, vm.movie_id, vm.videotype
ORDER BY vm.watched_on desc
LIMIT 6

视频存储在两个表中:如果 Viewedmovies 中的视频为1,它将从视频表中查询,并且 videotype 是否为0 ,它将从 channel_programmes channel_videos 进行查询。此查询返回结果,但不按日期顺序返回。

http://sqlfiddle.com/#!2/0c382/1

任何人都可以帮我解决这个问题吗?提前谢谢。

1 个答案:

答案 0 :(得分:0)

http://sqlfiddle.com/#!2/0c382/55

SELECT vm.watched_on,vm.movie_id,cp.channel_id,
v.title, v.videothumbnail, v.views, v.likes, v.length, v.videoid,
cp.title as videotitle, cv.thumbnail,cv.views as cvviews,cv.likes as cvlikes, cv.id,cp.starttime,cp.endtime,vm.videotype
FROM
(
     SELECT x.*
     FROM
     (
         SELECT user_id, movie_id, watched_on, videotype
         FROM viewedmovies
         ORDER BY watched_on DESC
     ) as x
     GROUP BY x.user_id, x.movie_id
) as vm
LEFT JOIN video as v
    ON (vm.movie_id=v.videoid AND vm.user_id=1 AND vm.videotype=1 and v.permission!=-1)
LEFT JOIN channel_videos as cv
    ON (vm.movie_id=cv.id AND vm.user_id=1 AND (vm.videotype=0 or vm.videotype=2))
LEFT JOIN channel_programmes as cp
    ON (vm.movie_id=cp.programme_source AND (vm.videotype=0 or vm.videotype=2) AND cp.status!=-1) 
WHERE vm.user_id=1 
ORDER BY vm.watched_on desc