The Python API Spec v2.0 contains the following:
.rowcount
This read-only attribute specifies the number of rows that
the last .execute*() produced (for DQL statements like
'select') or affected (for DML statements like 'update' or
'insert').
The attribute is -1 in case no .execute*() has been
performed on the cursor or the rowcount of the last
operation is cannot be determined by the interface. [7]
Note: Future versions of the DB API specification could
redefine the latter case to have the object return None
instead of -1.
...and, under Major changes from Version 1 to version 2...
The definition of the .execute() return value changed.
Previously, the return value was based on the SQL statement
type (which was hard to implement right) -- it is undefined
now; use the more flexible .rowcount attribute
instead. Modules are free to return the old style return
values, but these are no longer mandated by the
specification and should be considered database interface
dependent.
Consequently, I believe the change to sql.py update() and delete()
methods should be to change
self._db._execute(query)
to
self._db._execute(query)
return self._db._cursor.rowcount
I will test this with sqlite3 and mysql - can anyone with access to
other db's confirm that rowcount is supported?
On Dec 15, 11:33 pm, billf <[email protected]> wrote:
> Ok - I will try to determine if there is a "standard" way to do this.
> Can you tell me whether the drivers for the current supported
> databases conform to any particular specification? Python Database
> API Specification v2.0 seems the appropriate one but I'd like it
> confirmed.
>
> On Dec 15, 7:17 pm, mdipierro <[email protected]> wrote:
>
> > I would very much like to include this but this has to work on all
> > supported databases. Can you send me a patch? It will be included.
>
> > On Dec 15, 2:26 am, billf <[email protected]> wrote:
>
> > > I would like access to the rowcount returned from update and delete
> > > actions. There are a couple of reasons:
>
> > > a) it could be used to detect rare errors, e.g. expect 1 row to be
> > > updated and zero returned.
>
> > > b) if the update/delete affects several rows, I'd like to know how
> > > many rows were updated without running a separate select, e.g.
> > > rowcount=db(db.employee.role==request.vars.role).update(request.vars)
>
> > > I believe that this can be achieved quite simply by a patch to sql.py
> > > update() and delete() methods.
>
> > > Change "self._db._execute(query)" to "return self._db._execute(query)"
>
> > > If you wanted to access "rowcount" with SQLFORM then other changes
> > > would be required.
>
> > > My questions are:
>
> > > 1) can anyone see a problem with the suggestion?
>
> > > 2) does anyone object to including the proposed patch?
--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups
"web2py Web Framework" group.
To post to this group, send email to [email protected]
To unsubscribe from this group, send email to
[email protected]
For more options, visit this group at
http://groups.google.com/group/web2py?hl=en
-~----------~----~----~----~------~----~------~--~---
