query() method sends a
SQL query to the database. If
the query is an insert statement, the return value is the
OID of the newly inserted row.
If it is otherwise a query that does not return a result (i.e.,
is not a some kind of SELECT statement),
it returns None. Otherwise, it returns a
pgqueryobject that can be accessed
via the getresult() or dictresult() methods or simply printed.