How Query Statements Are Canceled
An application can cancel a query statement started with IIapi_query() before the statement is fully executed. To cancel a query statement, the application issues IIapi_cancel(), specifying the statement handle returned by IIapi_query(). IIapi_cancel() can be called anytime after IIapi_query() has returned with a status of “success.” If the query has already been completed, an error is returned to the application stating so.