[ @functname = ] 'procedure'

Is the name of the function to call within the dynamic-link library (DLL). procedure is nvarchar(517), with no default. procedure optionally can include the owner name in the form owner.function.

[ @dllname = ] 'dll'

Is the name of the DLL that contains the function. dll is varchar(255), with no default. It is recommended that you specify the complete path of the DLL.

0 (success) or 1 (failure)

None

After an extended stored procedure is created, it must be added to SQL Server by using sp_addextendedproc. For more information, see Adding an Extended Stored Procedure to SQL Server.

This procedure can be run only in the master database. To execute an extended stored procedure from a database other than master, qualify the name of the extended stored procedure with master.

sp_addextendedproc adds entries to the sys.objects catalog view, registering the name of the new extended stored procedure with SQL Server. It also adds an entry in the sys.extended_procedures catalog view.

Important:
Existing DLLs that were not registered with a complete path will not work after upgrading to SQL Server 2008. To correct the problem, use sp_dropextendedproc to unregister the DLL, and then reregister it with sp_addextendedproc, specifying the complete path.

Only members of the sysadmin fixed server role can execute sp_addextendedproc.

The following example adds the xp_hello extended stored procedure.

USE master
GO
EXEC sp_addextendedproc xp_hello, 'c:\xp_hello.dll'

Reference

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