Unit testing is an essential part of software development, ensuring that individual components of a system are functioning correctly. While there are many tools available for unit testing, testing SQL Server databases can be a challenge. In this article, we will explore how to automate SQL Server unit testing using SQL Load Test.

What is SQL Load Test?

SQL Load Test is a tool available on CodePlex that allows you to translate a SQL Profiler trace file into a Visual Studio C# file, generating unit tests for each entry in the trace file. This tool is specifically designed for testing deployed databases and can be a valuable addition to your unit testing strategy.

Getting Started with SQL Load Test

To get started with SQL Load Test, you will need to set up the SQL Profiler with specific columns and events. The required columns are EventClass, TextData, and DatabaseName. The required events are SQL:BatchStarting, RPC:Starting, Audit Login, and Audit Logout. The tool will ignore entries related to the master, model, and msdb databases, as well as entries with no database name and calls to sp_reset_connection.

Once the profiler is set up, you can start capturing a trace by having a user navigate through the application and perform various actions. After capturing the trace, save it to a file.

Generating Unit Tests

Using SQL Load Test is straightforward. It is a command-line application that requires three parameters: a name for the scenario, the path and name of the trace file, and an optional configuration file. The configuration file allows you to customize the generation of unit tests, but the default parameters are suitable for initial tests.

After running SQL Load Test, you will have a C# file containing the generated unit tests. Add this file to your project and configure the SQL connection string. You can then run the tests from Visual Studio and see the results.

Benefits of SQL Load Test

SQL Load Test offers several benefits for automating SQL Server unit testing:

• Real-life queries: Since the tests are based on database usage, you can have tests that reflect what users do. By running the profiler on the production server for a period of time, you can capture real-life queries and ensure the integrity of your databases.
• Performance monitoring: You can configure the Visual Studio Test Load Agent to monitor the performance of your SQL server during the execution of the tests. This allows you to simulate concurrent connections and identify any performance issues.
• Easy configuration: SQL Load Test provides a simple way to configure unit tests without needing to know the code behind your databases. This can be particularly useful when managing integrity checks on complex databases.

Conclusion

While there are many tools available for unit testing SQL Server databases, SQL Load Test offers a unique approach by allowing you to generate unit tests based on real-life queries. By automating SQL Server unit testing, you can ensure the integrity and performance of your databases, making it easier to release error-free builds.

Remember, SQL Load Test is just one tool in your unit testing arsenal. It should not replace the unit tests that developers should perform on the database solution. However, it can be a valuable addition, especially when dealing with complex databases and managing integrity checks.