pg_num_rows() will return the
number of rows in a PostgreSQL
result resource.
result is a query result resource returned by
pg_query(). This function will return -1 on
error.
注: Use pg_affected_rows() to get number of rows affected by INSERT, UPDATE and DELETE query.
注: This function used to be called pg_numrows().
See also pg_num_fields() and
pg_affected_rows().