How do I SUM DISTINCT Rows?

Question

I\'m struggling with a query where I need to SUM DISTINCT Rows. There has to be a way to do this... but I\'m lost.

Here\'s what I\'ve got:

SELECT D         


        

Answer 1

An easy answer is use "group by". Group by has the same effect with the same fields as distinct, but allows you to use aggregate functions. You can add a "Having" clause after the group by to filter what records you would like to see.