SQL functions
SQL functions are functions implemented completely with SQL that can be used to encapsulate logic that can be invoked like a programming sub-routine. You can create SQL scalar functions and SQL table functions.
There are many useful applications for SQL functions within a database or database application architecture. SQL functions can be used to create operators on column data, for extending the support of built-in functions, for making application logic more modular, and for improving overall database design, and database security.
The following topics provide more information about SQL functions: