内部连接总和SQL

Question

我一直在尝试做一个SUM与内部连接，但它显示每个单元格而不是将它们添加在一起，并只显示在一个单元格中，我在哪里出错？

SELECT SUM(trans) as 'Transactions',city as 'city' 
FROM account 
INNER JOIN branch 
ON branch.bID 
GROUP BY account.trans, branch.city; 

Answer 1

单独添加branch.city使用下面的查询，将每个城市返回总和

SELECT SUM(trans) as 'Transactions', branch.city as 'city' 
FROM account 
INNER JOIN branch 
ON branch.bID = account.bID 
GROUP BY branch.city; 

Answer 2

在Group by删除account.trans。由于您在group by中添加了account.trans, branch.city，因此它会显示sum(trans)每trans和city。

如果你想sum(trans)每city然后在group by

SELECT SUM(trans) as 'Transactions' 
FROM account 
INNER JOIN branch 
ON branch.bID 
Group by branch.city;