int Ns_DbCancel( Ns_DbHandle *handle );
The Ns_DbCancel function is similar to the Ns_DbFlush function, but instead of allowing the select statement to complete and send all selected rows, Ns_DbCancel sends a cancels message to the database. This can result in faster interruption of a long-running query. Ns_DbCancel returns NS_OK on success and NS_ERROR on error.