diff options
Diffstat (limited to 'examples/inheritance/concrete.py')
| -rw-r--r-- | examples/inheritance/concrete.py | 142 |
1 files changed, 76 insertions, 66 deletions
diff --git a/examples/inheritance/concrete.py b/examples/inheritance/concrete.py index 258f41025..2245aa4e0 100644 --- a/examples/inheritance/concrete.py +++ b/examples/inheritance/concrete.py @@ -1,7 +1,14 @@ """Concrete-table (table-per-class) inheritance example.""" -from sqlalchemy import Column, Integer, String, \ - ForeignKey, create_engine, inspect, or_ +from sqlalchemy import ( + Column, + Integer, + String, + ForeignKey, + create_engine, + inspect, + or_, +) from sqlalchemy.orm import relationship, Session, with_polymorphic from sqlalchemy.ext.declarative import declarative_base from sqlalchemy.ext.declarative import ConcreteBase @@ -11,107 +18,105 @@ Base = declarative_base() class Company(Base): - __tablename__ = 'company' + __tablename__ = "company" id = Column(Integer, primary_key=True) name = Column(String(50)) employees = relationship( - "Person", - back_populates='company', - cascade='all, delete-orphan') + "Person", back_populates="company", cascade="all, delete-orphan" + ) def __repr__(self): return "Company %s" % self.name class Person(ConcreteBase, Base): - __tablename__ = 'person' + __tablename__ = "person" id = Column(Integer, primary_key=True) - company_id = Column(ForeignKey('company.id')) + company_id = Column(ForeignKey("company.id")) name = Column(String(50)) company = relationship("Company", back_populates="employees") - __mapper_args__ = { - 'polymorphic_identity': 'person', - } + __mapper_args__ = {"polymorphic_identity": "person"} def __repr__(self): return "Ordinary person %s" % self.name class Engineer(Person): - __tablename__ = 'engineer' + __tablename__ = "engineer" id = Column(Integer, primary_key=True) name = Column(String(50)) - company_id = Column(ForeignKey('company.id')) + company_id = Column(ForeignKey("company.id")) status = Column(String(30)) engineer_name = Column(String(30)) primary_language = Column(String(30)) company = relationship("Company", back_populates="employees") - __mapper_args__ = { - 'polymorphic_identity': 'engineer', - 'concrete': True - } + __mapper_args__ = {"polymorphic_identity": "engineer", "concrete": True} def __repr__(self): return ( "Engineer %s, status %s, engineer_name %s, " - "primary_language %s" % - ( - self.name, self.status, - self.engineer_name, self.primary_language) + "primary_language %s" + % ( + self.name, + self.status, + self.engineer_name, + self.primary_language, + ) ) class Manager(Person): - __tablename__ = 'manager' + __tablename__ = "manager" id = Column(Integer, primary_key=True) name = Column(String(50)) - company_id = Column(ForeignKey('company.id')) + company_id = Column(ForeignKey("company.id")) status = Column(String(30)) manager_name = Column(String(30)) company = relationship("Company", back_populates="employees") - __mapper_args__ = { - 'polymorphic_identity': 'manager', - 'concrete': True - } + __mapper_args__ = {"polymorphic_identity": "manager", "concrete": True} def __repr__(self): return "Manager %s, status %s, manager_name %s" % ( - self.name, self.status, self.manager_name) + self.name, + self.status, + self.manager_name, + ) -engine = create_engine('sqlite://', echo=True) +engine = create_engine("sqlite://", echo=True) Base.metadata.create_all(engine) session = Session(engine) -c = Company(name='company1', employees=[ - Manager( - name='pointy haired boss', - status='AAB', - manager_name='manager1'), - Engineer( - name='dilbert', - status='BBA', - engineer_name='engineer1', - primary_language='java'), - Person(name='joesmith'), - Engineer( - name='wally', - status='CGG', - engineer_name='engineer2', - primary_language='python'), - Manager( - name='jsmith', - status='ABA', - manager_name='manager2') -]) +c = Company( + name="company1", + employees=[ + Manager( + name="pointy haired boss", status="AAB", manager_name="manager1" + ), + Engineer( + name="dilbert", + status="BBA", + engineer_name="engineer1", + primary_language="java", + ), + Person(name="joesmith"), + Engineer( + name="wally", + status="CGG", + engineer_name="engineer2", + primary_language="python", + ), + Manager(name="jsmith", status="ABA", manager_name="manager2"), + ], +) session.add(c) session.commit() @@ -120,14 +125,15 @@ c = session.query(Company).get(1) for e in c.employees: print(e, inspect(e).key, e.company) assert set([e.name for e in c.employees]) == set( - ['pointy haired boss', 'dilbert', 'joesmith', 'wally', 'jsmith']) + ["pointy haired boss", "dilbert", "joesmith", "wally", "jsmith"] +) print("\n") -dilbert = session.query(Person).filter_by(name='dilbert').one() -dilbert2 = session.query(Engineer).filter_by(name='dilbert').one() +dilbert = session.query(Person).filter_by(name="dilbert").one() +dilbert2 = session.query(Engineer).filter_by(name="dilbert").one() assert dilbert is dilbert2 -dilbert.engineer_name = 'hes dilbert!' +dilbert.engineer_name = "hes dilbert!" session.commit() @@ -138,24 +144,28 @@ for e in c.employees: # query using with_polymorphic. eng_manager = with_polymorphic(Person, [Engineer, Manager]) print( - session.query(eng_manager). - filter( + session.query(eng_manager) + .filter( or_( - eng_manager.Engineer.engineer_name == 'engineer1', - eng_manager.Manager.manager_name == 'manager2' + eng_manager.Engineer.engineer_name == "engineer1", + eng_manager.Manager.manager_name == "manager2", ) - ).all() + ) + .all() ) # illustrate join from Company eng_manager = with_polymorphic(Person, [Engineer, Manager]) print( - session.query(Company). - join( - Company.employees.of_type(eng_manager) - ).filter( - or_(eng_manager.Engineer.engineer_name == 'engineer1', - eng_manager.Manager.manager_name == 'manager2') - ).all()) + session.query(Company) + .join(Company.employees.of_type(eng_manager)) + .filter( + or_( + eng_manager.Engineer.engineer_name == "engineer1", + eng_manager.Manager.manager_name == "manager2", + ) + ) + .all() +) session.commit() |