Press "Enter" to skip to content

Category: Testing

SQLCover

Published 2016-04-11 by Kevin Feasel

Ed Elliott has upgraded his T-SQL code coverage tool:

What is code coverage?

Code coverage is a way to see how many statements in your database code have been executed when you ran your tests(s). It is a way to see how well covered with tests a particular area is – the better covered with tests, the less likely you will miss issues when you make changes in those areas.

What is code coverage for SQL Server?

SQL Server gives us a great tracing mechanism, either profiler or extended events which details exactly which statements have been run. SQL Server doesn’t do so well at telling us what statements we could possibly run in some code but the Transact Sql Script Dom that is part of the DacFx does give us the ability to break T-SQL code into statements so combining the two we have the ability to take a stored procedure such as:

This is pretty snazzy.

Comments closed

When To Test

Published 2016-03-31 by Kevin Feasel

Kenneth Fisher thinks about when to test:

To test or not to test. That is the question. Or is it? Shouldn’t we always test? That was the question posted here. It’s a big question so let’s break it down a bit.

My short answer is:  test as much as necessary to keep two conditions from occurring:  first, that you get fired (or worse); second, that the inevitable bug somebody else discovers in your code is too embarrassing.  Kenneth’s answer is better.

Comments closed

Unit Testing A Function

Published 2016-02-17 by Kevin Feasel

Steve Jones walks through a practical example of unit testing T-SQL with tsqlt:

However I wanted to add some tests. Does this really work? What if I don’t have a backslash? I thought the best way to do this was with a few tSQLt tests, which I quickly built. The entire process was 5-10 minutes, which isn’t a lot longer than if I had been running random tests myself with a variety of strings.

The advantage of tests is that if I come up with a new case, or another potential bug, I copy the test over, change the string and I have a new test, plus all the regressions. I’m not depending on my memory to run the test cases.

I first put the code in a function, which makes it easier to test.

tsqlt is a great tool for database unit testing.

Comments closed

Code Coverage In SSDT

Published 2016-01-18 by Kevin Feasel

Ed Elliott continues to amaze me.  This time, he’s got a code coverage tool for T-SQL code:

If we execute this stored procedure we can monitor and show a) how many statements there are in this and also b) which statements have been called but we can’t see which branches of the case statement were actually called. If it was a compiled language like c# where we have a profiler that can alter the assembly etc then we could find out exactly what was called but I personally think knowing which statements are called is way better than having no knowledge of what level of code coverage we have.

Yet another reason to grab the SSDT Dev Pack.  By this point, I expect there to be a couple more reasons next week…

Comments closed

SQLQueryStress Source Code Now Available

Published 2016-01-05 by Kevin Feasel

Adam Machanic has made the SQLQueryStress source code publicly available:

So here’s the official word: The attached source code is hereby released to the world, copyright and royalty free. You may use it, if you like, for whatever you want. Enjoy! If you use it for a public project, I would appreciate a mention in the acknowledgements section, but even that is not required. This source code is yours, warts and all. I was tempted to do some cleanup work, but at this point it’s just not something I’m ever going to touch again. I upgraded the project from Visual Studio 2005 to Visual Studio 2013, confirmed that it builds and seems to work, and that’s that.

Adam may never have used in a production scenario, but I certainly have, and SQLQueryStress is still the best free load simulator.  There’s also a GitHub repo thanks to Erik Ejlskov Jensen, so go forth and hack at some C# code.

Comments closed