Beginning Microsoft SQL Server 2008 ... - S3 Tech Training

Now, I don’t know about you, but I get very suspicious when I hear the word “analysis” come out of
someone’s lips — particularly if that person is in a marketing or sales role. Don’t get me wrong — those
people are doing their jobs just like I am. The thing is, once they ask a question one way, they usually
want to ask the same question another way. That being the case, I went ahead and set this up as a
script — now all we need to do when they decide they want to try it with 15 percent is make a change to
the initialization value of @Markup. Let’s see what we got this time with that 10 percent markup though:
ProductID Name ListPrice Marked Up Price New Price
--------- ------------------------------ ----------- ---------------- -----------
990 Mountain-500 Black, 42 539.99 593.989 593.9500
980 Mountain-400-W Silver, 38 769.49 846.439 846.4900
970 Touring-2000 Blue, 46 1214.85 1336.335 1336.4900
960 Touring-3000 Blue, 62 742.35 816.585 816.7500
950 ML Crankset 256.49 282.139 282.4900
940 HL Road Pedal 80.99 89.089 89.4900
930 HL Mountain Tire 35.00 38.50 38.7500
920 LL Mountain Frame - Silver, 52 264.05 290.455 290.4900
910 HL Mountain Seat/Saddle 52.64 57.904 57.9500
900 LL Touring Frame - Yellow, 50 333.42 366.762 366.9500
(10 row(s) affected)
Look these over for a bit, and you’ll see that the results match what we were expecting. What’s more, we
didn’t have to build a cursor to do it.
Looping with the WHILE Statement
The WHILE statement works much as it does in other languages to which you have probably been
exposed. Essentially, a condition is tested each time you come to the top of the loop. If the condition is
still TRUE, then the loop executes again — if not, you exit.
The syntax looks like this:
WHILE
|
[BEGIN
[BREAK]
|
[CONTINUE]
END]
Chapter 11: Writing Scripts and Batches
While you can just execute one statement (much as you do with an IF statement), you’ll almost never
see a WHILE that isn’t followed by a BEGIN...END with a full statement block.
The BREAK statement is a way of exiting the loop without waiting for the bottom of the loop to come and
the expression to be re-evaluated.
I’m sure I won’t be the last to tell you this, but using a BREAK is generally thought of as something of
bad form in the classical sense. I tend to sit on the fence on this one. I avoid using them if reasonably
possible. Most of the time, I can indeed avoid them just by moving a statement or two around while still
359