Hi Massimo,
the issue is that delete can't work directly on the
google.appengine.ext.db.Query object. In the delete function, items is
an instance of that Query object, and has to be transformed into a
list of google.appengine.ext.db.Models - which is what the fetch
function does.
In fact, it doesn't have to be limited to 1000: the fetch function
takes an argument that can have any value - the example said 1000,
but any other value would be valid.
After playing around a bit, I reconsidered the fix to be:
def delete(self):
self._db['_lastsql'] = 'DELETE WHERE %s' % self.where
(items, tablename, fields) = self._select()
tableobj = self._db[tablename]._tableobj
counter = self.items_count(items)
leftitems = items.fetch(1000)
while len(leftitems):
gae.delete(leftitems)
leftitems = items.fetch(1000)
return counter
so that it removes items by 1000 increments. That should do the trick
for now, but I see room for performance improvement:
- allow the select function to retrieve keys only instead of the
entire entity, as the documentation explains that it's a lot faster
(and we don't need the full entity for a delete)
- counter = self.items_count(items) could be computed via
len(leftitems) and the 1000 increments
Christophe
On May 5, 12:10 am, mdipierro <[email protected]> wrote:
> Thank you for reporting this. Please check my fix in trunk.
>
> Massimo
>
> On May 4, 4:16 pm, Christophe Plat <[email protected]> wrote:
>
>
>
> > This issue on web2py is related to GAE issue 3119 (http://
> > code.google.com/p/googleappengine/issues/detail?id=3119).
> > I'm using web2py 1.77.3.
>
> > In gql.py, line 702 to 709:
>
> > def delete(self):
> > self._db['_lastsql'] = 'DELETE WHERE %s' % self.where
> > (items, tablename, fields) = self._select()
> > tableobj = self._db[tablename]._tableobj
> > counter = self.items_count(items)
> > if counter:
> > gae.delete(items)
> > return counter
>
> > According to comment 8 on issue 3119, the delete function no longer
> > works on Query object, which items is an instance of. It suggests to
> > change the code to either:
>
> > db.delete(<query>.fetch(1000))
>
> > or
>
> > db.delete(list(<query>))
>
> > with a preference to fetch(1000). In other words: a fix for this issue
> > is to update line 708 to:
>
> > gae.delete(items.fetch(1000))
>
> > It leaves open the issue of queries returning more than 1000 results,
> > though.
>
> > Best regards,
> > Christophe
