Microsoft® SQL Server 2012 Unleashed

Developing Managed User-Defined Types (UDTs)

In the preceding section, you used a managed user-defined type (UDT) called RegexPattern to store the regular expression pattern. In this section, you explore how custom UDTs are built and used in SQL Server.

The first thing to note is that although the name UDT is the same as the extended data types built using SQL Server 2000, they are by no means the same in SQL Server 2012. SQL Server 2000’s UDTs were actually retro-named “alias data types” in SQL Server 2005. SQL Server 2012 UDTs are structs (value types) built using the .NET Framework.

To create a UDT of your own, you right-click your Visual Studio project and then select Add, User-Defined Type. Next, you should name both the class and its autogenerated ...