A query with Sum() and how to add more fields to it.

[sepoto]

SELECT FullCityName, Sum(Population)
FROM Duplicates
GROUP BY FullCityName;

I tried adding another field:

SELECT FullCityName, ZipCode, Sum(Population)
FROM Duplicates
GROUP BY FullCityName;

Do I have to use a join? If so what would the structure have to look like? I'm wondering why does "FullCityName," result in a functional query but "FullCityName, ZipCode" result in an "aggregate function" error? I need to get this down.

[pbaldy]

Any field in the select clause that is not aggregated (Sum, Avg, Max, etc) needs to be in the GROUP BY clause. Try


SELECT FullCityName, ZipCode, Sum(Population)
FROM Duplicates
GROUP BY FullCityName, ZipCode

[sepoto]

That is the answer. It works very well.

SELECT FullCityName, ZipCode, Sum(Population)
FROM Duplicates
GROUP BY FullCityName, ZipCode;

[pbaldy]

Happy to help.