I very much appreciate this article as we've all had a similar problem at one time or another and they always seem to pop up when you have an after work appointment.
I would, however, like to caution folks that may read it because there are a couple of things that were done that, in my eyes as a professional "data handler", are grounds for instant termination of employment.
The ReportDay = 29 and in 2009 there were only 28 days in February. You fixed this value:
It's just not up to you to "fix" data simply because you don't know what the data should actually be. For example, Yakov points out that a bad date was found because there is no Feb 29th of 2009 because 2009 wasn't a Leap Year. Yakov fixed that by changing the 29 to a 28 and everything is hunky dory, right? Wrong! What if it was the year that was fat fingered and the year should have been 2008 or the month should have been a 1 or a 3, instead? You don't know for sure and you must not make such a presumption.
Never ever make such a presumption... just list it as an exception on the report. It's not up to you to make what could be an incorrect decision. While you're at it, I believe I'd also take the small bit of time to write down the fact that, considering the adjacent data, it's not likely that Feb 2009 actually occurred in the 3rd "Quater". It takes just 2 seconds to demonstrate that you're concerned about the data enough to help the company that's making it possible for you to afford the home you so desperately want to get to. 😉
On to the next problem...
You review your query and decide that if multiple expenses where entered the same date (Tiebreaker) the max expense becomes the last one and it has max(RowId) for each contractor. You modify your query and it produce a correct result.
Who gave you the authority to make such a decision? Just because it's an "ad hoc" report doesn't justify such a poor decision. The first thing you should do on the very first day you report to work (or, hopefully during the interview) is to get your manager's telephone number. Certainly, if your manager gives you such an "urgent" request and you don't have your manager's telephone number, take out 5 seconds to find out what it is. Your manager gave you the urgent request because (s)he trusts you to not only get the job done, but to contact them if ANYTHING goes wrong. Why are you violating that trust? Your manager may not know the data but, upon hearing about it, may actually want to see ALL the charges on that last day for each contactor.
While I appreciate the fact that we all have "real" lives to live and outside appointments to keep, there are certain shortcuts that you simply must not take no matter how urgent the in-house request is nor how urgent your outside appointment is. You're being paid good money to be a professional and professionals don't ever take such shortcuts nor make such willy-nilly decisions about the data. 2 very bad decisions were made in the process of solving this urgent request and the manager should have been contacted immediately for both.
There's a huge difference between getting the urgent job done in time and getting the job right. One of those differences may be whether you have a job to come to tomorrow because the two infractions I've cited above have set the manager up for potential failure and that you can't actually be trusted with data. 😉
Slow down... be professional... do it right all the time! Data isn't the only thing that's supposed to have some integrity to it.
--Jeff Moden
Change is inevitable... Change for the better is not.