The inserts work great. But when I try to do a select query it fails with postgres. Sqlite works fine though. Script included. Error message: sqlalchemy.exceptions.SQLError: ('(ProgrammingError) UNION types text and integer cannot be matched\n',) |
from sqlalchemy import * import sys, sets # this example illustrates a polymorphic load of two classes, where each class has a very # different set of properties
metadata = BoundMetaData('sqlite://', echo='debug')
# a table to store companies
companies = Table('companies', metadata,
Column('company_id', Integer, primary_key=True),
Column('name', String(50)))
# we will define an inheritance relationship between the table "people" and "engineers",
# and a second inheritance relationship between the table "people" and "managers"
people = Table('people', metadata,
Column('person_id', Integer, primary_key=True),
Column('company_id', Integer, ForeignKey('companies.company_id')),
Column('name', String(50)),
Column('type', String(30)))
engineers = Table('engineers', metadata,
Column('person_id', Integer, ForeignKey('people.person_id'), primary_key=True),
Column('status', String(30)),
Column('engineer_name', String(50)),
Column('primary_language', String(50)),
)
managers = Table('managers', metadata,
Column('person_id', Integer, ForeignKey('people.person_id'), primary_key=True),
Column('status', String(30)),
Column('manager_name', String(50))
)
metadata.create_all()
# create our classes. The Engineer and Manager classes extend from Person.
class Person(object):
def __init__(self, **kwargs):
for key, value in kwargs.iteritems():
setattr(self, key, value)
def __repr__(self):
return "Ordinary person %s" % self.name
class Engineer(Person):
def __repr__(self):
return "Engineer %s, status %s, engineer_name %s, primary_language %s" % (self.name, self.status, self.engineer_name, self.primary_language)
class Manager(Person):
def __repr__(self):
return "Manager %s, status %s, manager_name %s" % (self.name, self.status, self.manager_name)
class Company(object):
def __init__(self, **kwargs):
for key, value in kwargs.iteritems():
setattr(self, key, value)
def __repr__(self):
return "Company %s" % self.name
# create a union that represents both types of joins.
person_join = polymorphic_union(
{
'engineer':people.join(engineers),
'manager':people.join(managers),
'person':people.select(people.c.type=='person'),
}, None, 'pjoin')
#person_mapper = mapper(Person, people, select_table=person_join, polymorphic_on=person_join.c.type, polymorphic_identity='person')
person_mapper = mapper(Person, people, select_table=person_join,polymorphic_on=person_join.c.type, polymorphic_identity='person')
mapper(Engineer, engineers, inherits=person_mapper, polymorphic_identity='engineer')
mapper(Manager, managers, inherits=person_mapper, polymorphic_identity='manager')
mapper(Company, companies, properties={
'employees': relation(Person, lazy=False, private=True, backref='company')
})
session = create_session(echo_uow=False)
c = Company(name='company1')
c.employees.append(Manager(name='pointy haired boss', status='AAB', manager_name='manager1'))
c.employees.append(Engineer(name='dilbert', status='BBA', engineer_name='engineer1', primary_language='java'))
c.employees.append(Person(name='joesmith', status='HHH'))
c.employees.append(Engineer(name='wally', status='CGG', engineer_name='engineer2', primary_language='python'))
c.employees.append(Manager(name='jsmith', status='ABA', manager_name='manager2'))
session.save(c)
print session.new
session.flush()
#sys.exit()
session.clear()
c = session.query(Company).get(1)
for e in c.employees:
print e, e._instance_key, e.company
assert sets.Set([e.name for e in c.employees]) == sets.Set(['pointy haired boss', 'dilbert', 'joesmith', 'wally', 'jsmith'])
print "\n"
dilbert = session.query(Person).get_by(name='dilbert')
dilbert2 = session.query(Engineer).get_by(name='dilbert')
assert dilbert is dilbert2
dilbert.engineer_name = 'hes dibert!'
session.flush()
session.clear()
c = session.query(Company).get(1)
for e in c.employees:
print e, e._instance_key
session.delete(c)
session.flush()
metadata.drop_all()
On 16-jun-2006, at 21:03, Michael Bayer wrote: you got it...small fix to some foreign key arithmetic in changeset 1630. |
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