If this function is implemented and exposed in the external library, it is executed by the database server immediately before unloading the external library.
extern "C" void SQL_CALLBACK extfn_pre_unload_library( void );
This function is required only if there is a library-specific requirement to do library-wide cleanup before the library is unloaded.
This function is called asynchronously by the database server immediately before unloading the external library.
extern "C" __declspec( dllexport ) void SQL_CALLBACK extfn_pre_unload_library( void ) { MessageBox( NULL, "Library unloading", "SQL Anywhere", MB_OK | MB_TASKMODAL ); }
Syntax