pg_result_status() returns
status of result resource. Possible retun values are
PGSQL_EMPTY_QUERY, PGSQL_COMMAND_OK, PGSQL_TUPLES_OK,
PGSQL_COPY_TO, PGSQL_COPY_FROM, PGSQL_BAD_RESPONSE,
PGSQL_NONFATAL_ERROR and PGSQL_FATAL_ERROR.
See also pg_connection_status().