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在MySQL中连接表和聚合数据?_Mysql - Fatal编程技术网

在MySQL中连接表和聚合数据?

在MySQL中连接表和聚合数据?,mysql,Mysql,我有两张桌子。成员及其项目。我需要提取所有用户,以及他们的项目数量,按项目数量排序 表:用户: id | username | email | password | reg_date 表:项目: id | title | descr | autor 对于连接: projects.autor = users.id SELECT users.id, users.username, COUNT(projects.id) AS `num_projects` FROM user

我有两张桌子。成员及其项目。我需要提取所有用户,以及他们的项目数量,按项目数量排序

表:
用户

id | username | email | password | reg_date
表:
项目

id | title    | descr | autor
对于连接:

projects.autor = users.id
SELECT
  users.id,
  users.username,
  COUNT(projects.id) AS `num_projects`
FROM
  users
LEFT OUTER JOIN
  projects
ON
  projects.autor = users.id
GROUP BY
  users.id
ORDER BY
  num_projects DESC
SELECT u.id AS id, u.username AS username, u.email AS email, u.password AS password, u.reg_date AS reg_date, COUNT(p.id) AS projects_count 
FROM users u
LEFT OUTER JOIN projects p ON p.autor = u.id
GROUP BY u.id 
ORDER BY projects_count DESC