Application locks aren't a well known area of locking in SQL Server, but they can be very useful for special scenarios. They work in a analogous way to the lock() construct in .Net and are basicaly user defined mutexes in SQL Server.

Locking is a major part of every RDBMS and is important to know about. It is a database functionality which without a multi-user environment could not work.

Using MBUnit's awesome Rollback attribute for unit tests cause the test to be wrapped in a transaction - which is well and good as that allows any changes made by the test to be undone. However, it also causes a database lock contention when you try to read from a locked row/table while debugging yo...