id summary reporter owner description type status component version severity resolution keywords cc stage has_patch needs_docs needs_tests needs_better_patch easy ui_ux 2361 QuerySet.filter(m2mfield__isnull=False) may return duplicates daniel.tietze@… Norbert Stüken "My Django installation is SVN Revision: 3238 Filtering models by a ManyToMany field does not appear to work. See Google groups thread http://groups.google.com/group/django-users/browse_thread/thread/d0d799a45cb92d35 I have two classes -- Blog and Submission: {{{ class Blog( models.Model ): entries = models.ManyToManyField( Submission ) class Submission( models.Model ): [... whatever ] }}} I want to fetch a list of all Blog instances which have at least one Submission , i.e. entries.count() > 0. The suggested {{{ Blog.objects.filter(entries__isnull = False) }}} (suggested by Malcolm Tredinnick) returns: {{{ psycopg.ProgrammingError: FEHLER: Spalte m2m_models_blog__entries.entries existiert nicht SELECT ""models_blog"".""id"",""models_blog"".""title"",""models_blog"".""description"",""models_blog"".""region_id"",""models_blog"".""regionname"",""models_blog"".""date_submitted"",""models_blog"".""author_id"",""models_blog"".""visible"" FROM ""models_blog"" LEFT OUTER JOIN ""models_blog_entries"" AS ""m2m_models_blog__entries"" ON ""models_blog"".""id"" = ""m2m_models_blog__entries"".""blog_id"" WHERE (""m2m_models_blog__entries"".""entries"" IS NOT NULL) }}} m2m_models_blog__entries is an alias for models_blog_entries -- I *have* this table, but it has no column ""entries"". This is what it looks like: {{{ # \d models_blog_entries Tabelle »public.models_blog_entries« Spalte | Typ | Attribute ---------------+---------+--------------------------------------------------------------------- id | integer | not null default nextval('public.models_blog_entries_id_seq'::text) blog_id | integer | not null submission_id | integer | not null Indexe: »models_blog_entries_pkey« PRIMARY KEY, btree (id) »models_blog_entries_blog_id_key« UNIQUE, btree (blog_id, submission_id) Fremdschlüssel-Constraints: »models_blog_entries_blog_id_fkey« FOREIGN KEY (blog_id) REFERENCES models_blog(id) »models_blog_entries_submission_id_fkey« FOREIGN KEY (submission_id) REFERENCES models_submission(id) }}} Also, if I do this: {{{ Blog.objects.filter(entries__blog__id__isnull = False) }}} I get a list of Blogs which have entries, however I have duplicates in the list, one for each Submission which is in a M2M relationship (i.e. each Blog is shown n times if it has n entries). " Bug assigned Database layer (models, ORM) dev normal Fabio Sangiovanni Accepted 0 0 0 0 0 0