如何在使用内部联接时计算结果

Question

我在下面有一个简单的查询，它基本上过滤了每个分支的储蓄帐户。

SELECT Account.bID as Branch,branch.bAddress.street as Street, branch.bAddress.city as City, branch.bAddress.postcode as Postcode, Account.accType as Type
FROM Account
INNER JOIN branch
ON Account.bID=branch.bID where accType='savings';

我正在尝试添加计数，因此不显示列表，而是显示每个分支的储蓄帐户金额。我不太确定我在哪里添加这个特定查询的计数。

感谢任何帮助。

Answer 1

SELECT branch.bid, branch.bAddress.street as Street, 
branch.bAddress.city as City, branch.bAddress.postcode as Postcode,   
count(account.*) as savings_count
FROM Account
INNER JOIN branch
ON Account.bID=branch.bID where accType='savings'
group by branch.bid, branch.bAddress.street, 
branch.bAddress.city, branch.bAddress.postcode;

Answer 2

只需在count(*)和select中添加group by：

SELECT a.bID as Branch, b.bAddress.street as Street, b.bAddress.city as City,
       b.bAddress.postcode, a.accType as Type, COUNT(*)
FROM Account a INNER JOIN
     branch b
     ON a.bID = b.bID
WHERE accType = 'savings'
GROUP BY a.bID, b.bAddress.street, b.bAddress.city, b.bAddress.postcode;

这已经用别名替换了表名，因此更容易阅读。但是，某些列（例如b.bAddress.street）不是有效的SQL。