Can't be sure without the models, but if enty.tags is a rel field (ForeignKey, ManytoMany), doing entry.tags_list will probably cause that second query.
Also, where is the name tags_list coming from? In the Entry query I only see "zinnia_entry"."tags", but to get a rel mapping I would normally call entry.tags_set, not tags_list. On Wednesday, September 11, 2013 10:51:54 AM UTC-5, [email protected] wrote: > > (I'm porting an app and originally posted this in its mailing list but > it's been a day and I haven't gotten a response. If that's not a good > enough reason for cross-posting, sorry and feel free to ignore me.) > > I'm using python 3.3 and django 1.6 . > > I have this code: > with self.assertNumQueries(1) as q: > all_entries = list(Entry.objects.all()) > print("All entries: ", all_entries) > for entry in all_entries: > print("Entry: ", entry, " , Tags list: ", entry.tags_list) > for query in q.captured_queries: > print(query, "\n") > > which produces this output (slightly edited for prettiness): > > All entries: [<Entry: My entry: published>] > Entry: My entry: published , Tags list: [] > > {'time': '0.000', 'sql': 'QUERY = \'SELECT "zinnia_entry"."id", > "zinnia_entry"."title", "zinnia_entry"."slug", "zinnia_entry"."status", > "zinnia_entry"."start_publication", "zinnia_entry"."end_publication", > "zinnia_entry"."creation_date", "zinnia_entry"."last_update", > "zinnia_entry"."content", "zinnia_entry"."comment_enabled", > "zinnia_entry"."pingback_enabled", "zinnia_entry"."trackback_enabled", > "zinnia_entry"."comment_count", "zinnia_entry"."pingback_count", > "zinnia_entry"."trackback_count", "zinnia_entry"."excerpt", > "zinnia_entry"."image", "zinnia_entry"."featured", "zinnia_entry"."tags", > "zinnia_entry"."login_required", "zinnia_entry"."password", > "zinnia_entry"."content_template", "zinnia_entry"."detail_template" FROM > "zinnia_entry" ORDER BY "zinnia_entry"."creation_date" DESC\' - PARAMS = > ()'} > > {'time': '0.000', 'sql': 'QUERY = \'SELECT "tagging_tag"."id", > "tagging_tag"."name" FROM "tagging_tag" INNER JOIN "tagging_taggeditem" ON > ( "tagging_tag"."id" = "tagging_taggeditem"."tag_id" ) WHERE > ("tagging_taggeditem"."content_type_id" = %s AND > "tagging_taggeditem"."object_id" = %s ) ORDER BY "tagging_tag"."name" ASC\' > - PARAMS = (12, 1)'} > > (I get the same queries if I don't print out the entry or its tag list. I > just retained the print loop to show that it doesn't have any tags) > > Entry.objects is the standard db.models.Manager type and as far as I can > tell, it has not been monkeypatched anywhere. > > Obviously, I got two queries instead of just the one that I was expecting. > I can't find any reason for the second query. I'm especially confused > because the entry clearly doesn't even have a tag (as demonstrated by the > empty tags_list). Would anyone happen to have any idea how querying for one > model can lead to a query for another model type? If not, do you have any > suggestions for me in debugging the issue? > > I've already checked if the __str__ method of the Model somehow references > the object mentioned in the second query and it doesn't. (I can remove the > print calls and it'll still be triggered anyway.) > > Thanks > -- You received this message because you are subscribed to the Google Groups "Django users" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/django-users. For more options, visit https://groups.google.com/groups/opt_out.
