Method checkCursorClosed

src/yvalve/why.cpp:1267–1272

		}

		void checkCursorClosed() const
		{
			if (statement && statement->cursor)
				(Arg::Gds(isc_sqlerr) << Arg::Num(-502) <<
					Arg::Gds(isc_dsql_cursor_open_err)).raise();
		}

		IStatement* getInterface()
		{