User-Defined Functions and Types
In this chapter, I’ll present recipes for user-defined functions and types. User-defined functions (UDFs) allow you to encapsulate both logic and subroutines into a single function that can then be used within your Transact-SQL queries and programmatic objects. User-defined types (UDTs) allow you to create an alias type based on an underlying system data type, enforcing a specific data type, length, and nullability.
In this chapter, I’ll also cover the SQL Server user-defined table type, which can be used as a user-defined table parameter for passing table result sets within your T-SQL ...