内连接总和SQL

Question

I have been trying to do a SUM with inner join, however it shows each cell rather than adding them together and showing only in one cell, where am I going wrong?

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

Answer 1

Remove account.trans in Group by . Since you added account.trans, branch.city in group by it will show sum(trans) per trans and city .

If you want sum(trans) per city then add branch.city alone in group by

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

Answer 2

Use the following query which will return the sum per city

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