Hmm. I believe our ```import_data``` command sets all property_id to be equal to the values in [the csv file](https://github.com/codefordurham/Durham-Data/blob/master/Restaurants/2014-1-14-Establishments.csv) and in that file all property_id values are set to 0. I am not 100% about the origins of this file, but I was working with what I had.
This is further corroborated by a database check:
```
 >>> len(Establishment.objects.filter(Q(property_id=0)))
4416
>>> len(Establishment.objects.filter(~Q(property_id=0)))
1074
>>> len(Establishment.objects.all())
5490
```
The 1074 establishments with non-zero property_id were set by the ```importer.py``` from this commit.