MySQL流行的行基于不同的时间级别

Question

我有2张桌子:photo和like.我试图在一天内根据喜欢的数量获得流行的照片.所以基本上就像'今天​​流行'.

SELECT
  p.id AS id, COUNT(li.id) AS total_likes \
FROM `photo` p \
  LEFT JOIN `like` li \
    ON p.id = li.photo_id \
WHERE
  li.date > DATE_SUB(CURDATE(), INTERVAL 1 DAY) \
GROUP BY \
  p.id

当今天有足够数量的喜欢时,这很有效.但如果过去一天没有喜欢,它将不会返回任何记录.

我也想稍微改变一下.是否有可能达到水平？例如:
根据多天排名照片:

1. Get photos based on how many likes today
2. Get photos based on how many likes for last week
and so on...

所以基本上它的作用是,假设我们需要得到30个项目.首先,它会尝试根据今天有多少喜欢来获取行.它可以是任何数字20,15等.然后它将获得总共30个所需的剩余行,但现在将根据一周中有多少喜欢进行排序.

So something like:
SELECT FROM photo SORT BY likes today, likes in a week ...

谢谢你的帮助!

Answer 1

您可以根据 CASE 计算不同的计数，例如过去 30 天的计数和最后一天的计数。上周和过去 30 天：

SELECT
  p.id AS id
  ,COUNT(CASE WHEN li.DATE > DATE_SUB(CURDATE(), INTERVAL 1 DAY) THEN li.id END) AS daily_likes
  ,COUNT(CASE WHEN li.DATE > DATE_SUB(CURDATE(), INTERVAL 7 DAY) THEN li.id END) AS weekly_likes
  ,COUNT(li.id) AS total_likes
FROM `photo` p
JOIN `LIKE` li
    ON p.id = li.photo_id
WHERE
  li.DATE > DATE_SUB(CURDATE(), INTERVAL 30 DAY)
GROUP BY
  p.id
ORDER BY daily_likes DESC, weekly_likes DESC, total_likes DESC
LIMIT 30

我不知道你的限制是基于哪个定义，它可能是这样的

SELECT *
FROM
 (
   SELECT
     p.id AS id
     ,COUNT(CASE WHEN li.DATE > DATE_SUB(CURDATE(), INTERVAL 1 DAY) THEN li.id END) AS daily_likes
     ,COUNT(CASE WHEN li.DATE > DATE_SUB(CURDATE(), INTERVAL 7 DAY) THEN li.id END) AS weekly_likes
     ,COUNT(li.id) AS total_likes
   FROM `photo` p
   JOIN `LIKE` li
       ON p.id = li.photo_id
   WHERE
     li.DATE > DATE_SUB(CURDATE(), INTERVAL 30 DAY)
   GROUP BY
     p.id
  ) AS dt
ORDER BY
   case when daily_likes > 20 then daily_likes else 0 end desc,
   case when weekly_likes > 100 then weekly_likes else 0 end desc,
   total_likes DESC
LIMIT 30