1 files changed, 106 insertions, 0 deletions
diff --git a/examples/dogpile_caching/model.py b/examples/dogpile_caching/model.py
new file mode 100644
index 000000000..6f1cffedf
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+++ b/examples/dogpile_caching/model.py
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+"""Model.   We are modeling Person objects with a collection
+of Address objects.  Each Address has a PostalCode, which
+in turn references a City and then a Country:
+
+Person --(1..n)--> Address
+Address --(has a)--> PostalCode
+PostalCode --(has a)--> City
+City --(has a)--> Country
+
+"""
+from sqlalchemy import Column, Integer, String, ForeignKey
+from sqlalchemy.orm import relationship
+from caching_query import FromCache, RelationshipCache
+from environment import Base, bootstrap
+
+class Country(Base):
+    __tablename__ = 'country'
+
+    id = Column(Integer, primary_key=True)
+    name = Column(String(100), nullable=False)
+
+    def __init__(self, name):
+        self.name = name
+
+class City(Base):
+    __tablename__ = 'city'
+
+    id = Column(Integer, primary_key=True)
+    name = Column(String(100), nullable=False)
+    country_id = Column(Integer, ForeignKey('country.id'), nullable=False)
+    country = relationship(Country)
+
+    def __init__(self, name, country):
+        self.name = name
+        self.country = country
+
+class PostalCode(Base):
+    __tablename__ = 'postal_code'
+
+    id = Column(Integer, primary_key=True)
+    code = Column(String(10), nullable=False)
+    city_id = Column(Integer, ForeignKey('city.id'), nullable=False)
+    city = relationship(City)
+
+    @property
+    def country(self):
+        return self.city.country
+
+    def __init__(self, code, city):
+        self.code = code
+        self.city = city
+
+class Address(Base):
+    __tablename__ = 'address'
+
+    id = Column(Integer, primary_key=True)
+    person_id = Column(Integer, ForeignKey('person.id'), nullable=False)
+    street = Column(String(200), nullable=False)
+    postal_code_id = Column(Integer, ForeignKey('postal_code.id'))
+    postal_code = relationship(PostalCode)
+
+    @property
+    def city(self):
+        return self.postal_code.city
+
+    @property
+    def country(self):
+        return self.postal_code.country
+
+    def __str__(self):
+        return "%s\t"\
+              "%s, %s\t"\
+              "%s" % (self.street, self.city.name,
+                self.postal_code.code, self.country.name)
+
+class Person(Base):
+    __tablename__ = 'person'
+
+    id = Column(Integer, primary_key=True)
+    name = Column(String(100), nullable=False)
+    addresses = relationship(Address, collection_class=set)
+
+    def __init__(self, name, *addresses):
+        self.name = name
+        self.addresses = set(addresses)
+
+    def __str__(self):
+        return self.name
+
+    def __repr__(self):
+        return "Person(name=%r)" % self.name
+
+    def format_full(self):
+        return "\t".join([str(x) for x in [self] + list(self.addresses)])
+
+# Caching options.   A set of three RelationshipCache options
+# which can be applied to Query(), causing the "lazy load"
+# of these attributes to be loaded from cache.
+cache_address_bits = RelationshipCache(PostalCode.city, "default").\
+                and_(
+                    RelationshipCache(City.country, "default")
+                ).and_(
+                    RelationshipCache(Address.postal_code, "default")
+                )
+
+bootstrap()
+\ No newline at end of file