Database Engine Extended Stored Procedure Programming
This feature will be removed in a future version of Microsoft SQL Server. Do not use this feature in new development work, and modify applications that currently use this feature as soon as possible. Use CLR Integration instead. For more information, see Common Language Runtime (CLR) Integration Programming Concepts.
The Microsoft Extended Stored Procedure API provides a server-based application programming interface (API) for extending Microsoft SQL Server functionality. The API consists of C and C++ functions and macros used to build applications in the following categories: extended stored procedures and gateway applications.
Extended stored procedures allow you to create your own external routines in a programming language such as C. The extended stored procedures appear to users as typical stored procedures and are executed in the same way. Parameters can be passed to extended stored procedures, and they can return results and return status.