Monthly Archives: July 2012
SQL Saturday #122 | Louisville, KY on July 21, 2012 was the 5th SQL Saturday I have attended so far, and my 3rd as a speaker. The St.Louis contingent – Kathi Kellenberger, Kim Tessereau, Mike Lynn, Jay Carter, Cindy Baker and me ! – was especially excited to attend this event, not only because it’s organized by our friend Malathi Mahadevan, but also for a chance to escape the St.Louis heat !
We had almost forgotten about the time zone change when we drove into Louisville at 6 PM Central sharp, only to realize we were an hour late for the speakers’ dinner! The Bristol Bar & Grille was the perfect location for a great speakers’ dinner, and gave us all a chance to relax, network and enjoy some good food (My personal favorite was the Espresso Crème Brûlée).
University of Louisville is a short 10 minute drive from the Marriot Hotel, and thanks to the email notifications with directions, as well as plenty of signs, we had no trouble finding the venue. Thanks to SPEEDPASS, there were no lines at the registration desk and I found they had my favourite Asiago Cheese Bagels for breakfast! My first session for the day was Andy Thiru‘s “SQL Azure Intro and What’s New” session and it surely exceeded my expectations. I have never had the opportunity to work with SQL Azure so far, and this session gave me the knowledge and tools to get me started on my own. The next session on my list was “What Sequence objects are (and are not)” by Louis Davidson. I used to be an Oracle DBA until a few years ago, and took sequences for granted, until I discovered SQL Server doesn’t have them (until 2012). With their introduction in SQL Server 2012, I took this opportunity to get myself reacquainted with Sequences.
I had some delicious Veggie Wraps and a Cookie for lunch – again, no lines and no waiting! Post lunch, I took a break in the Speakers’ Lounge to review my upcoming session on Parameter Sniffing, where I discovered a cooler full of Ice Cream! I had to stop myself after two servings and got back to reviewing my slides & checking my demos. A majority of the attendees for my session were quite involved with the topic, giving rise to several discussions and Q&A, thus making my session all the more valuable for everyone in the room. I was really pleased with the generous evaluations and great feedback for my session.
The last session of the day for me was “Bulletproof: Hardening your SQL Server from Attack” by Sarah Barela. As a developer, I take care of hardening my code against SQL Injection, but usually let administrators worry about securing the servers and databases. This session revealed the amount of work administrators (Database, Server as well as Network) put in to secure our servers ! After the last session, it was time for the closing ceremonies and Raffle. The SQL Saturday #122 Team hosted a great event with a full day of valuable SQL learning. I am really thankful to the SQL Saturday #122 Team for giving me the opportunity to present my session, and the support of all the sponsors to making such events possible.
I am looking forward to see my friends from Louisville again, at SQL Saturday #154 in St.Louis on Sept 15th , the very first SQL Saturday in St.Louis !
While brushing up on my knowledge of software testing concepts, I came across quite an amusing definition of testing; “To tell somebody that he is wrong is called criticism. To do so officially is called testing” . A programmer usually resents it when a tester finds a defect in his code. We programmers thoroughly unit test our code before handing it off to a tester, because we take pride in developing a bug free application. Some programming languages (C# , VB, ASP.NET) afford themselves to be unit testing easily, because the application is developed within Visual Studio and can readily leverage its unit testing framework.
Visual Studio allows you to create Database projects, and database developers have started embracing it since Visual Studio Team Systems 2008 Database Edition GDR. This offers a robust framework for database developers to identify bugs with their database objects (schemas, stored procedures, functions, etc) by unit testing their database (T-SQL) code, before handing it over to the tester. Before we jump into the specifics of database unit testing with Visual Studio, the next couple of paragraphs warm us up to the topic by covering a few basic concepts of software testing.
Software testing, undoubtedly plays a important role in the life cycle of most IT Projects. The Goal of any type of software testing is to identify defects to be fixed, so that the product meets requirements and has a deterministic and predictable output. Depending on the testing method employed, testing can be implemented at any time in the development process. Different software development models will focus the test effort at different phases in the development process. Newer development models, such as Agile, often employ test driven development and place an increased portion of the testing in the hands of the developer, before it reaches a formal team of testers.
Software testing methods are traditionally divided into white and black-box testing. These two approaches are used to describe the point of view that a test engineer takes when designing test cases. Unit Testing falls under the category of white box testing, where the the tester has access to the internal data structures and algorithms, including the code that implements these. This is in contrast with the black-box testing method, which treats the software as a “black box”—without any knowledge of internal implementation. A black box tester is usually not a programmer, and aims to only test the functionality of software according to the applicable requirements. Since the black-box tester has no knowledge on the underlying code, he may find bugs that a programmer misses. However, the same principle can sometimes lead to writing inefficient or incomplete test cases.
Unit Testing is a key component of Test driven development (TDD). Unit Tests are usually written by Developers while they work on the code, to ensure that a specific of piece of code (Function, Class, Stored procedure, etc) is working as expected. Unit Testing helps to identify defects in the earlier stages of the software development life cycle, where they are cheaper to fix. Unit Testing can prove especially challenging in the world of database development, because of the need for a consistent test environment.
Database Unit Tests are used to establish a baseline state for a database and then to verify any subsequent changes that you make to database objects. The Unit Testing Framework in Visual Studio (starting with VSTS 2005) helps database developers create, manage and execute Unit Tests for a Database. The Microsoft.VisualStudio.TestTools.UnitTesting namespace supplies classes that provide unit testing support. This namespace contains many attributes that identify test information to the test engine regarding data sources, order of method execution, program management, agent/host information, and deployment data. It also contains custom unit testing exceptions.
You will need the Database Edition GDR of VSTS 2008 or the Ultimate (or Premium) Editions of VSTS 2010 to create, modify and run database unit tests. You can run database unit tests with Professional Edition on VSTS 2010, but cannot create or modify them. Before you can start running database unit tests in VSTS, you must first create a Database Project and then create a test project. The next step is to write sets of Transact-SQL tests that exercise your database objects. Executing these tests in your isolated development environment helps you to verify whether those objects are behaving correctly before you check them in to version control. As changes are made to the database schema, you can use these tests to verify whether the changes have broken existing functionality. A detailed step by step walk through for creating and running database unit tests can be found here on MSDN . Once Created, a Unit Test Project and of the tests will show up in the Solution Explorer View;
In a typical database unit test, a Transact-SQL test script runs and returns an instance of the ExecutionResult class. The instance of this class contains a DataSet, the execution time, and the rows affected by the script. All of this information is collected during execution of the script. These results can be evaluated within the Transact-SQL script by using the RAISERROR function, or they can be evaluated by using test conditions. Visual Studio Premium provides a set of the following predefined test conditions for you to use;
- Data Checksum
- Empty Resultset
- Execution Time
- Expected Schema
- Not Empty Resultset
- Row Count
- Scalar Value
- Run multiple unit tests as a group
- Run tests as a part of a Build
- Enforce check-in policy
- Software Testing Principles, Terminology & Definitions – http://en.wikipedia.org/wiki/Software_testing
- Unit Testing Framework in Visual Studio –
- Database Unit Testing with Visual Studio –
- Unit Test Conditions in Database Unit Tests – http://msdn.microsoft.com/en-us/library/aa833423
- Test Lists – http://msdn.microsoft.com/en-us/library/ms182461.aspx
- Visual Studio 11 (Beta) Unit Testing updates – http://blogs.msdn.com/b/visualstudioalm/archive/2012/03/08/what-s-new-in-visual-studio-11-beta-unit-testing.aspx
- Software Testing Jokes – http://softwaretestingfundamentals.com/software-testing-jokes/