Question

我有以下SQL语句：

    SELECT 
    O.id,
    O.name,
    (SELECT 
            COUNT(U.id)
        FROM
            User U
        WHERE
            U.organization_id = O.id) AS num_users
FROM
    Organization O

User表和Organization表由名为organization_id

的东西绑定

当我执行此语句时，我得到了以下（坏）结果：

id |  name   | num_users
------------------------
 1 |  MyOrg  |     2
 2 |  MyOrg  |     0
 3 | testOrg |     0

任何人都可以告诉我如何得到一个只会产生1行pr的结果。组织？

请注意，我已尝试使用DISTINCT但未获得更好的结果

Answer 1

SQL Fiddle演示以下查询：

SELECT GROUP_CONCAT(DISTINCT o.id SEPARATOR ', '), O.name, 
       COUNT(U.organization_id) AS MyCount
FROM Organization O
LEFT JOIN User U ON U.organization_id = O.id
GROUP BY O.name;

或者，如果您不需要id字段，那么：

SELECT O.name, COUNT(U.organization_id) AS MyCount
FROM Organization O
LEFT JOIN User U ON U.organization_id = O.id
GROUP BY O.name;

SQL Count返回太多行

1 个答案: