Ticket #5937: django-generic-relation-query.patch

django/db/models/query.py

@@ -960 +960 @@
     current_column = column
     intermediate_table = None
     join_required = False
+    generic_relation_required = False
 
     name = path.pop(0)
     # Has the primary key been requested? If so, expand it out
@@ -980 +981 @@
             # This process hijacks current_table/column to point to the
             # intermediate table.
             current_table = "m2m_" + new_table
-            intermediate_table = field.m2m_db_table()
             join_column = field.m2m_reverse_name()
-            intermediate_column = field.m2m_column_name()
-
+            from django.contrib.contenttypes.generic import GenericRelation
+            if not isinstance(field, GenericRelation):
+                intermediate_table = field.m2m_db_table()
+                intermediate_column = field.m2m_column_name()
+            else:
+                generic_relation_required = True
+                from django.contrib.contenttypes.models import ContentType
+                ct_obj = ContentType.objects.get(
+                    app_label=current_opts.app_label,
+                    model=current_opts.object_name.lower()
+                )
             raise FieldFound
 
         # Does the name belong to a reverse defined many-to-many field?
@@ -1060 +1069 @@
             # for the search. No need to join an extra table just
             # to check the primary key.
             new_table = current_table
+        elif generic_relation_required:
+            ct_field = new_opts.get_field(field.content_type_field_name)
+            pk_field = new_opts.get_field(field.object_id_field_name)
+            joins[qn(new_table)] = (
+                qn(new_opts.db_table), "INNER JOIN",
+                "%s.%s = %s.%s" % (qn(table), qn(current_opts.pk.column), qn(new_table), qn(pk_field.column))
+            )
+            where.append(get_where_clause('exact', qn(new_table) + '.',
+                         ct_field.column, ct_obj.id, ct_field.db_type()))
+            params.extend(field.get_db_prep_lookup('exact', ct_obj.id))
+            join_column = None
         else:
             # There are 1 or more name queries pending, and we have ruled out
             # any shortcuts; therefore, a join is required.