set num_columns to 0 if there are no more results
set num_columns to 0 if there are no more results

--HG--
extra : convert_revision : svn%3Acef11e0c-2622-11df-baa9-c5a8049e1931/trunk%40112

msabramo/_pymssql_2013-09-09,msabramo/_pymssql_2013-09-09,msabramo/_pymssql_2013-09-09