[SQL] GROUP by finish&&last day of month

[Antti Linno]

Ok, if I want to get non-aggregat data in groups, I use order by. This 
group by seemed so logical though, but the fruit that u can't have, is
usually the most sweet.

New question, how to get the last day of month(order data by last day of
month). And to prevent chain letter from misunderstanding, no I don't
intend to look it up from calendar and then input it manually. 

A.