Since I saw a request, I'll post a short overview of the outer join vs inner join. There is nothing really complex about them and you can read about them in a million SQL books, but I'll take a stab at it anyway. The most common scenario where outer joins...

I am going to proceed to some lengthy and boring esoterica of ORDER BY, but as a reminder, you can influence the choice of topics pretty easily by posting comments with your favorites :-). This posting is provided "AS IS" with no warranties, and confers...

So, when your query specification has an explicit GROUP BY, your choices in what to use in post-grouping clauses (SELECT, HAVING, ORDER BY) are limited. You can only use aggregate functions, expressions in the GROUP BY list, or constants. An interesting...