On Nov 3, 2011, at 9:33 AM, Chris Withers wrote:
> Hi All,
>
> Any idea what this traceback is about?
> This query normally works fine and is run a few hundred times a day ;-)
if you use the DBAPI and you say:
cursor = conn.cursor()
cursor.execute("UPDATE XYZ set foo=bar")
if you were to then try to look at the list of "columns returned by this
query", that is, cursor.description, you'd get None. Why is that ? Because
we just did an UPDATE statement, no columnar results are returned. description
is None.
If our UPDATE happened to use a RETURNING type of clause, assuming this is
supported by both database and DBAPI we *would* get a result set back, and
cursor.description should be present.
Anyway, SQLAlchemy raises the error you see if you call fetchone()/all() on a
result set where cursor.description is not present.
Why query(X).with_lockmode('update').all() is doing this appears to be some bug
in your DBAPI, because all() emits a SELECT unconditionally.
>
> cheers,
>
> Chris
>
> -------- Original Message --------
> session.query(PasswordRequest).with_lockmode('update').all():
> File "SQLAlchemy-0.6.6-py2.6.egg/sqlalchemy/orm/query.py", line 1579, in all
> return list(self)
> File "SQLAlchemy-0.6.6-py2.6.egg/sqlalchemy/orm/query.py", line 1791, in
> instances
> fetch = cursor.fetchall()
> File "SQLAlchemy-0.6.6-py2.6.egg/sqlalchemy/engine/base.py", line 2498, in
> fetchall
> l = self.process_rows(self._fetchall_impl())
> File "SQLAlchemy-0.6.6-py2.6.egg/sqlalchemy/engine/base.py", line 2467, in
> _fetchall_impl
> self._non_result()
> File "SQLAlchemy-0.6.6-py2.6.egg/sqlalchemy/engine/base.py", line 2472, in
> _non_result
> "This result object does not return rows. "
> sqlalchemy.exc.ResourceClosedError: This result object does not return rows.
> It has been closed automatically.
>
> --
> You received this message because you are subscribed to the Google Groups
> "sqlalchemy" group.
> To post to this group, send email to sqlalchemy@googlegroups.com.
> To unsubscribe from this group, send email to
> sqlalchemy+unsubscr...@googlegroups.com.
> For more options, visit this group at
> http://groups.google.com/group/sqlalchemy?hl=en.
>
--
You received this message because you are subscribed to the Google Groups
"sqlalchemy" group.
To post to this group, send email to sqlalchemy@googlegroups.com.
To unsubscribe from this group, send email to
sqlalchemy+unsubscr...@googlegroups.com.
For more options, visit this group at
http://groups.google.com/group/sqlalchemy?hl=en.
