CODEWITHSUNDEEP
mysqlsqldatabase
Aaron
Aaron

Reputation: 85

Calculating sum based on CustomerID

Okay so I'm trying to help my friend with a query.

The question asks to calculate the amount owed by each customer, and display the TotalAmount, CustomerName and CustomerID.

We tried this:

SELECT SUM(balance) AS totalBalance, customerName, customerID
FROM invoices;

This seems simple enough, but I'm afraid this won't give each customer a unique sum, and I can't test these until tomorrow because I don't have access to a database program at the moment.

Upvotes: 0

Views: 74

Answers (1)

AdamMc331
AdamMc331

Reputation: 16730

If you want to sum a value, you need to make a group. Otherwise, how would MySQL know which values to sum? I assume in this case you will group by customerID, but that is just assumption.

Try this:

SELECT customerID, customerName, SUM(balance)
FROM invoices
GROUP BY customerID;

EDIT The above query assumes your customerID is unique and that it would be sufficient enough to group by that. If it's not unique, it would be a good idea to group by customerID and name like so:

GROUP BY customerID, customerName;

Upvotes: 2

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