Sybase 12.4.2 manual Creating procedures and functions with external calls, 269

CHAPTER 6 Using Procedures and Batches

This section describes how to use the external library calls in procedures.

Warning! External libraries can corrupt your database.

External libraries called from procedures share the memory of the server. If you call a DLL from a procedure and the DLL contains memory-handling errors, you can crash the server or corrupt your database. Ensure that your libraries are thoroughly tested before deploying them on production databases.

Creating procedures and functions with external calls

This section presents some examples of procedures and functions with external calls.

For a full description of the CREATE PROCEDURE statement syntax, see

“CREATE PROCEDURE statement” in Adaptive Server IQ Reference Manual.

For a full description of the CREATE FUNCTION statement syntax for

	external calls, see “CREATE FUNCTION statement” in Adaptive Server IQ
	Reference Manual.
	Note You must have DBA permissions in order to create external procedures
	or functions. This requirement is more strict than the RESOURCE permissions
	required for creating other procedures or functions.
Syntax
	A procedure that calls a function function_name in DLL library.dll can be
	created as follows:
	CREATE PROCEDURE dll_proc ( parameter-list )
	EXTERNAL NAME ’function_name@library.dll’
	Such a procedure is called an external stored procedure. If you call an
	external DLL from a procedure, the procedure cannot carry out any other tasks;
	it just forms a wrapper around the DLL.
	An analogous CREATE FUNCTION statement is as follows:
	CREATE FUNCTION dll_func ( parameter-list )
	RETURNS data-type
	EXTERNAL NAME ’function_name@library.dll’

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