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Worst Practices - Part 1 of a Very Long Series!


In our business we spend a lot of time talking about 'Best Practices' - ways of doing things that over time have proved to be the most effective (or accurate, or whatever...). There are a couple problems with Best Practices. One is that there is no 'book' of them, they are scattered across a hundred books and websites and you often need one sentence out of all that information. Another is that whether something is a Best Practice is often less than clear - it depends on your attitude towards problem solving, your experience, your situation. Finally, sometimes Best Practices (let's just use BP from here on) can be a trap, keeping you from looking at solutions that clearly defy BP but yet might be an ideal solution to your problem.

Interesting so far?

Between our discussion forums and email I receive, I see a lot of questions about how to do things. It's interesting to participate in those discussions - usually the person asking the question just needs to solve the problem and could care less about BP - but it's often revealed that BP would have avoided the question in the first place! Another thing I see a lot is that the question the reader asks points to a larger issue - something I call Worst Practices (WP). They are trying to solve the wrong problem - we'll get to some examples shortly. As I thought about that, it occurred to me that many readers might benefit from a discussion of why some things are sooooo bad. The interesting thing about WP is I think they map to the easiest path of solving a problem. I say that because I think if you give a junior developer or DBA a problem, 8 times out of 10 their solution will be one of brute force. Now before I begin, please understand I'm not mocking anyone for asking a question. One thing you'll notice in our discussion forums is a high degree of politeness. Our mission here is to help our readers with SQL Server issues and even issues that are closely related. Those beginner questions provide us with an incredible opportunity to educate the reader who asked...and all those who read the thread during and after the discussion.

In the months ahead I'll be addressing many WP items, but for today let's start with a simple one - using Hungarian Notation for Column Names. If you're not familiar with Hungarian Notation, take a quick look at this article on MSDN. Basically it's a technique of naming your variables so that they include both scope and data type information.

Declare @LoopCounter int
Declare @iLoopCounter int

In this example, the second declare uses Hungarian Notation - I've used the 'i' prefix to denote that it's an integer value. Once you get used to it, it's a huge time saver, you don't have to scroll back to the top to find the declare to see it's data type. The down side of course is that when you need to change it to a bigint, you have two choices:

Declare @biLoopCounter bigint
Declare @iLoopCounter bigint

You can do a search and replace on the variable name in your procedure to reflect the data type (BP) or you can just change the data type (WP). Of course, if you didn't use Hungarian then you just change the data type. I use VB a lot and Hungarian is pretty common there, after a while it's comfortable and the occasional extra effort of changing a variable name is more than offset by the gains in readability. I'll leave it up to you to decide if Hungarian is a BP when coding.

Now let's look at something closer to our hearts, a table! Take a hard core VB programmer who uses Hungarian for their grocery lists and what do you get for column names?

iQuantity    (int)
bIsComplete (bit)

Is that cool or what? Same naming syntax, same benefits of readability - why would I call this a WP? Make a few tables using this naming convention. Then build a few views, some stored procedures, maybe a user defined function or two, plus have three or four developers coding against it for a month. Now decide that a bit value for IsComplete isn't going to work, you're going to need to change it to a tinyint so you can have more than two status values. Think the column name will get changed? Ain't gonna happen! It's just too expensive for too little return.

Agree with me? Or not? Click on the discussion tab below and tell me what you think about WP in general and about this specific example of a WP.

Read the other articles in this series.


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