Adding integrity checks for ties between Works, Editions, and Identifiers

core/management/commands/check_works_integrity.py

@@ -1,5 +1,6 @@
 from django.core.management.base import BaseCommand
 from regluit.core import models
+from django.db.models import Q, F
 
 class Command(BaseCommand):
     help = "Do a few integrity checks on Works, Editions, and Identifiers"
@@ -13,3 +14,13 @@ class Command(BaseCommand):
         print "Number of Identifiers not tied to Works (should be 0): ",  \
             models.Identifier.objects.filter(work__isnull=True).count()
         print "Number of Editions not tied to a Work (should be 0): ", models.Edition.objects.filter(work__isnull=True).count()
+        print "Number of Ebooks not tied to an Edition (should be 0): ", models.Ebook.objects.filter(edition__isnull=True).count()
+        
+        # is the possibility of problems coming from the fact that there are two places to tie
+        # Work and Edition -- 1) foreign key Edition.work = models.ForeignKey("Work", related_name="editions", null=True)
+        #                     2) sharing the same Identifier.
+        # check both that iff a pair of Work and Edition share an identifier, that Work and Edition have a foreign key relationship
+        print "Number of Works that have editions->identifiers that don't lead back to the same work (should be 0): ", models.Work.objects.filter(~Q(editions__identifiers__work__id = F('id'))).count()
+        # check that for all Identifier pairs with an Edition that Edition<->Work foreign key relationships ties the same Edition/Work
+        print "Number of Identifier pairs with an Edition in which Edition<->Work foreign key relationships does not tie the same Edition/Work (should be 0): ",  \
+           models.Identifier.objects.filter(edition__isnull=False).filter(~Q(edition__work__id = F('edition__work__id'))).count()