內連接總和SQL

Question

我一直在嘗試使用內部聯接進行SUM，但是它顯示每個單元而不是將它們加在一起並僅在一個單元中顯示，那我在哪里做錯了？

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

Answer 1

刪除Group by account.trans 。 由於您添加了account.trans, branch.city group by account.trans, branch.city將顯示每個trans和city sum(trans) 。

如果要每個city sum(trans)則在group by單獨添加branch.city

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

Answer 2

使用以下查詢將返回每個城市的總和

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