Django ORM integration¶

Operations that cause synchronisation¶

.filter(...) operations make a CDMS API call to get the CDMS objects with the same translated filtering, refresh the local objects by updating or creating them and then return the standard Django results.

.get(...) operations get the object in local and in CDMS, compare the two, update the local one if needed and then return the standard Django result.

.create(...) or .save() operations create the object in local and in CDMS. In case of exceptions with CDMS the local changes are rolled back.

.save() operations update the object in local and in CDMS. In case of exceptions with CDMS the local changes are rolled back.

.delete() operations delete the object in local and in CDMS. In case of exceptions with CDMS the local changes are rolled back.

✔ Supported ✘ Not supported

Lookups¶
API	Description
✔ Klass.objects.filter(field__exact=...)
✔ Klass.objects.filter(field__iexact=...)
✔ Klass.objects.filter(field__contains=...)
✔ Klass.objects.filter(field__icontains=...)
✘ Klass.objects.filter(field__in=...)
✔ Klass.objects.filter(field__gt=...)
✔ Klass.objects.filter(field__gte=...)
✔ Klass.objects.filter(field__lt=...)
✔ Klass.objects.filter(field__lte=...)
✔ Klass.objects.filter(field__startswith=...)
✔ Klass.objects.filter(field__istartswith=...)
✔ Klass.objects.filter(field__endswith=...)
✔ Klass.objects.filter(field__iendswith=...)
✘ Klass.objects.filter(field__range=...)
✔ Klass.objects.filter(field__year=...)
✔ Klass.objects.filter(field__day=...)
✘ Klass.objects.filter(field__week_day=...)
✔ Klass.objects.filter(field__hour=...)
✔ Klass.objects.filter(field__minute=...)
✔ Klass.objects.filter(field__second=...)
✘ Klass.objects.filter(field__isnull=...)	Not yet implemented but we should really support it.
✘ Klass.objects.filter(field__search=...)
✘ Klass.objects.filter(field__regex=...)
✘ Klass.objects.filter(field__iregex=...)

Filtering¶
API	Description
✔ Klass.objects.all()	It only syncs the top 50 objects from CDMS as it would be infeasible to sync all of them.
✔ Klass.objects.filter(field=...)
✔ Klass.objects.filter(Q(field=...))
✔ Klass.objects.filter(field1=..., field2=...)
✔ Klass.objects.filter(Q(field1=...) & Q(field2=...))
✔ Klass.objects.filter(Q(field1=...) \| Q(field2=...))
✔ Klass.objects.filter(field1=...).filter(field2=...)
✔ Klass.objects.filter(Q(Q(field1=...) & Q(field2=...)) & Q(field3=...))
✔ Klass.objects.exclude(field=...)
✔ Klass.objects.exclude(field1=..., field2=...)
✔ Klass.objects.exclude(field1=...).exclude(field2=...)
✔ Klass.objects.exclude(Q(field1=...) \| Q(field2=...))
✔ Klass.objects.exclude(Q(field1=...) & Q(field2=...))
✔ Klass.objects.filter(field1=...).exclude(field2=...)
✔ Klass.objects.filter(Q(field1=...) \| Q(field2=...)).exclude(Q(field3=...) & Q(field4=...))

Order by¶
API	Description
✔ Klass.objects.all().order_by(‘field’)
✔ Klass.objects.all().order_by(‘-field’)
✔ Klass.objects.all().order_by(‘field1’, ‘-field2’)
✘ Klass.objects.all().order_by(‘?’)

Get¶
API	Description
✔ Klass.objects.get(pk=...)	Gets the obj from local, the one in CDMS, compares the two and updates the local before returning it if necessary
✔ Klass.objects.get(cdms_pk=...)	Gets the obj from local or CDMS if doesn’t exist in local, updates or creates the local before returning it if necessary
✔ Klass.objects.get(field=...)	Like .get(pk=...)

Create¶
API	Description
✔ obj = Klass(field=...); obj.save()
✔ Klass.objects.create(field=...)
✘ Klass.objects.bulk_create(...)

Update¶
API	Description
✔ obj.save()
✘ Klass.objects.filter(field=...).update(...)
✘ Klass.objects.select_for_update(...)

Delete¶
API	Description
✔ obj.delete()
✘ Klass.objects.filter(field=...).delete()

Misc¶
API	Description
✘ Klass.objects.annotate(...)
✘ Klass.objects.reverse(...)
✘ Klass.objects.distinct(...)
✘ Klass.objects.values(...)
✘ Klass.objects.values_list(...)
✘ Klass.objects.dates(...)
✘ Klass.objects.datetimes(...)
✔ Klass.objects.none()
✘ Klass.objects.select_related(...)
✘ Klass.objects.prefetch_related(...)
✘ Klass.objects.extra(...)
✘ Klass.objects.defer(...)
✘ Klass.objects.only(...)
✘ Klass.objects.raw(...)
✘ Klass.objects.get_or_create(...)
✘ Klass.objects.update_or_create(...)
✘ Klass.objects.count(...)
✘ Klass.objects.in_bulk(...)
✘ Klass.objects.latest(...)
✘ Klass.objects.earliest(...)
✘ Klass.objects.first(...)
✘ Klass.objects.last(...)
✘ Klass.objects.aggregate(...)
✘ Klass.objects.exists(...)

Operations that skip synchronisation¶

Most of the time, you can skip CDMS operations by using the skip_cdms() method on the manager or the skip_cdms param on the save/delete methods.

Note

Do not skip the cdms operations when writing as the objects would then become out of sync. If this is really required, maybe we need to rename the modified field into something like cdms_modified and have a different one for modified.

✔ Supported ✘ Not supported

Filtering¶
API	Description
✔ Klass.objects.skip_cdms().all()
✔ Klass.objects.skip_cdms().filter(...)
✔ Klass.objects.skip_cdms().exclude(...)
✔ Klass.objects.skip_cdms().all().order_by(...)

Get¶
API	Description
✔ Klass.objects.skip_cdms().get()

Create¶
API	Description
✔ obj = Klass(field=...); obj.save(skip_cdms=True)
✔ Klass.objects.skip_cdms().create(field=...)
✔ Klass.objects.skip_cdms().bulk_create(field=...)

Update¶
API	Description
✔ obj.save(skip_cdms=True)
✔ Klass.objects.skip_cdms().filter(field=...).update(...)
✔ Klass.objects.skip_cdms().select_for_update(...)

Delete¶
API	Description
✔ obj.delete(skip_cdms=True)
✔ Klass.objects.skip_cdms().filter(field=...).delete()

Misc¶
API	Description
✔ Klass.objects.skip_cdms().annotate(...)
✔ Klass.objects.skip_cdms().reverse(...)
✔ Klass.objects.skip_cdms().distinct(...)
✔ Klass.objects.skip_cdms().values(...)
✔ Klass.objects.skip_cdms().values_list(...)
✔ Klass.objects.skip_cdms().dates(...)
✔ Klass.objects.skip_cdms().datetimes(...)
✔ Klass.objects.skip_cdms().none()
✔ Klass.objects.skip_cdms().select_related(...)
✘ Klass.objects.skip_cdms().prefetch_related(...)
✔ Klass.objects.skip_cdms().extra(...)
✔ Klass.objects.skip_cdms().defer(...)
✔ Klass.objects.skip_cdms().only(...)
✔ Klass.objects.skip_cdms().raw(...)
✔ Klass.objects.skip_cdms().get_or_create(...)
✔ Klass.objects.skip_cdms().update_or_create(...)
✔ Klass.objects.skip_cdms().count(...)
✔ Klass.objects.skip_cdms().in_bulk(...)
✔ Klass.objects.skip_cdms().latest(...)
✔ Klass.objects.skip_cdms().earliest(...)
✔ Klass.objects.skip_cdms().first(...)
✔ Klass.objects.skip_cdms().last(...)
✔ Klass.objects.skip_cdms().aggregate(...)
✔ Klass.objects.skip_cdms().exists(...)