計數SQL - 兩個表

Question

我有兩個表： 隊（ID，姓名）和用戶（ID，姓名，TEAM_ID）

我想下面的結果：

Team | Members 
team1 | 10 
team2 | 14 
team3 | 8 

我嘗試：

SELECT t.name AS 'Team', COUNT(u.email) AS 'Members' FROM teams t INNER JOIN users u ON (u.team_id = t.id) 

但它不會工作。

Answer 1

您應該使用GROUP BY，你有別名語法錯誤，試試這個：

SELECT t.name AS `Team`, COUNT(u.email) AS `Members` 
FROM teams t INNER JOIN users u ON (u.team_id = t.id) 
GROUP BY t.name -- or t.id 

Answer 2

您需要GROUP BY球隊名稱值：

SELECT t.name AS `Team`, 
     COUNT(u.email) AS `Members` 
FROM teams t 
INNER JOIN users u ON u.team_id = t.id 
GROUP BY t.name