Models look similar to typical Django models. A neo4django model definition might look like this:
from neo4django.db import models class Person(models.NodeModel): name = models.StringProperty() age = models.IntegerProperty() friends = models.Relationship('self',rel_type='friends_with')
As you can see, some basic properties are provided:
class OnlinePerson(Person): email = models.EmailProperty() homepage = models.URLProperty()
Some property types can also be indexed by neo4django. This will speed up subsequent queries based on those properties:
class EmployedPerson(Person): job_title = models.StringProperty(indexed=True)
All instances of
EmployedPerson will have their
job_title properties indexed.
For a list of included property types, check out
Relationships are simple. Instead of
Relationship. In addition to the
relationship target, you can specify a relationship type and direction,
cardinality, and the name of the relationship on the target model:
class Pet(models.NodeModel): owner = models.Relationship(Person, rel_type='owns', single=True, related_name='pets' )
Note that specifying cardinality with
related_single is optional-
Neo4j doesn’t enforce any relational cardinality. Instead, these options are
provided as a modeling convenience.
You can also target a model that has yet to be defined with a string:
class Pet(models.NodeModel): owner = models.Relationship('Person', rel_type='owns', single=True, related_name='pets' )
And then in the interpreter:
>>> pete = Person.objects.create(name='Pete', age=30) >>> garfield = Pet.objects.create() >>> pete.pets.add(garfield) >>> pete.save() >>> list(pete.pets.all()) [<Pet: Pet object>]
If you care about the order of a relationship, add the
preserve_ordering=True option. Related objects will be retrieved in the
order they were saved.
Got a few models written? To learn about retrieving data, see Querying.