Question

我在SQL中有三个表：

video : ID, TITLE
join_video_clicked : ID_VIDEO, NB_VIEW
join_video_category : ID_VIDEO, ID_CATEGORY

我的实际SQL查询：

SELECT ID,TITLE,THUMB 
FROM video 
WHERE ID 
IN (
      SELECT * FROM 
      (
         SELECT ID_VIDEO 
         FROM join_video_clicked
         WHERE ID_VIDEO 
         IN 
         (
             SELECT ID_VIDEO 
             FROM join_video_category 
             WHERE ID_CATEGORY = 8
         ) 
    ORDER BY CLICKED DESC
  ) AS TEMP
 ) LIMIT 0,24

解释1：

SELECT ID_VIDEO FROM join_video_clicked ORDER BY CLICKED DESC LIMIT 0,24

此查询可获得最多查看的24个

解释2：

SELECT ID_VIDEO FROM join_video_category WHERE ID_CATEGORY = 8

此查询从自定义类别

获取ID

解释3：

SELECT ID,TITLE FROM video WHERE ID IN (!!!SUBQUERY!!!)

此查询使用子查询

查找id和title

我希望您的帮助可以调整我的查询，以便按照正确的顺序从自定义类别中获取最常查看的24个视频，因为通过此查询，我在自定义类别中查看的视频次数最多，但不符合DESC的顺序。

Answer 1

试试这个，

allowLargeResults

Answer 2

您可以在两个表之间进行内部联接以获取该类别中的所有视频，并且在该查询中，您可以添加订单并限制：

SELECT jvclick.id_video
FROM join_video_clicked jvclick
JOIN join_video_category jvcat ON jvcat.id_video = jvclick.id_video
ORDER BY jvclick.clicked DESC
LIMIT 24;

Answer 3

这样的事情应该这样做：

select
    vid.id_video,
    vid.title,
    count(click.id_video) cnt
from
    video_clicked click
    join video vid on click.id_video = vid.id_video
    join video_category cat on vid.id_video = cat.id_video
where
    cat.id_category = 1
group by
    vid.id_video,
    vid.title
order by 
    cnt desc
;

完整示例：

use example;

/*
video : ID, TITLE
join_video_clicked : ID_VIDEO, NB_VIEW
join_video_category : ID_VIDEO, ID_CATEGORY
*/

drop table if exists video_clicked;
drop table if exists video_category;
drop table if exists video;
drop table if exists category;

create table category (
    id_category int primary key,
    name varchar(256)
);

create table video (
    id_video int primary key,
    title varchar(256)
);

create table video_category (
    id_video int references video(id),
    id_category int references category(id)

);

create table video_clicked (
    id_video int references video(id),
    nb_view varchar(256)
);

select
    vid.id_video,
    vid.title,
    count(click.id_video) cnt
from
    video_clicked click
    join video vid on click.id_video = vid.id_video
    join video_category cat on vid.id_video = cat.id_video
where
    cat.id_category = 1
group by
    vid.id_video,
    vid.title
order by 
    cnt desc
;

Answer 4

SELECT v.ID,v.TITLE,v.THUMB FROM video v 
JOIN join_video_clicked jvc ON v.ID=jvc.ID_VIDEO
JOIN join_video_category jvcat ON v.ID=jvcat.ID_VIDEO
WHERE jvcat.ID_CATEGORY = 8 ORDER BY jvc.CLICKED DESC LIMIT 24

SQL其中IN Order 2 SubQuery

4 个答案: