Comments by fordc03 (Top 5 by date)

The template he has written won't do that. You'd have to use Invoice ID for that to work. Typically you'd do a self join on a customerID and t2.InvoiceID <= t1.InvoiceID to get that ordering.

Reason for my vote of 3
I previously voted this a 2, but upon further reflection he is right that this will do a running total...The query example is simply poorly defined in my opinion and lacks the explanation that this works well only when you have one aggregate that you want to return without condtional filters.

Reason for my vote of 2
This is a triangular join and is very resource intensive. You are also not guaranteed order of the sum operation as SQL pulls the data. This kind of query would choke a large data set.

Reason for my vote of 4
For most people this is the easiest way to implement a running total. Although many MVP's and diehards will tell you this is not a guaranteed method. It's been pretty reliable for me.