在 MySQL 中進行計數

Question

我有以下兩個表——userprofile 和 videoinfo。 videoInfo 對用戶配置文件有一個 FK。

CREATE TABLE `userprofile_userprofile` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `full_name` varchar(100) NOT NULL,
   ...
 )

CREATE TABLE `userprofile_videoinfo` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `title` varchar(256) NOT NULL,
  `uploaded_by_id` int(11) NOT NULL,
  ...
  KEY `userprofile_videoinfo_e43a31e7` (`uploaded_by_id`),
  CONSTRAINT `uploaded_by_id_refs_id_492ba9396be0968c` FOREIGN KEY (`uploaded_by_id`) REFERENCES `userprofile_userprofile` (`id`)
)

什么是 SQL 語句，用於顯示每個用戶配置文件的視頻數量並按 COUNT 排序？

Answer 1

SELECT u.id as userId, count(v.uploaded_by_id) as videosCount
FROM userprofile_userprofile u
    LEFT OUTER JOIN userprofile_videoinfo v
        ON v.uploaded_by_id = u.id
GROUP BY u.id
ORDER BY count(v.uploaded_by_id) DESC

Answer 2

SELECT uploaded_by_id, COUNT(ID) as cnt
FROM userprofile_videoinfo
GROUP BY uploaded_by_id
ORDER BY cnt DESC;