Useful Links

TSQLUnit

• Test-Driven Development of T-SQL Code -- an article by Louis Roy in SQLServerCentral.com on 2008/10/20. Detailed explanation on how to work with TSQLUnit.
• Unit Testing and Code Generation by Grant Fritchey in SQLServerCentral.com, 2006/06/20

Database testing

• Series of articles by Alex Kuznetsov
  • Close These Loopholes in Your Database Testing
  • Close Those Loopholes: Stress-Test those Stored Procedures
  • Close these Loopholes - Reproduce Database Errors

TDD and such

• Test Infected: Programmers Love Writing Tests - An article by Kent Beck and Erich Gamma
• Beck Testing Framework - A paper describing the original Smalltalk framework
• JUnit Primer - How to write tests for JUnit (Java).
• utPLSQL - An implementation of xUnit for Oracle.
• Refactoring relies on being able to run tests to check you haven't broken anything with your 'enhancements' and frequent testing is an essential part of extreme programming (XP), for more details see Extreme Programming: A gentle introduction, and the home site http://www.xprogramming.com/ where you'll also find implementations of xUnit for other languages
• The c2 wiki has a lot of information, some starting points are UnitTest or TestDrivenDevelopment.