Question

我有两张桌子

class Department(Model):
    id = Column(Integer, primary_key=True)
    employees = relationship('Employee', backref='department')

class Employee(Model):
    id = Column(Integer, primary_key=True)
    name = Column(String)
    department_id = Column(Integer, ForeignKey('department.id'))
    email_addresses = relationship('EmailAddress', backref='employee')

class EmailAddress(Model):
    id = Column(Integer, primary_key=True)
    value = Column(String)
    employee_id = Column(Integer, ForeignKey('employee.id'))

现在我需要找到所有拥有电子邮件地址为X的员工的部门。

当允许每位员工只有一个电子邮件地址时返回（因此他们email_address = Column(String)我使用了此代码，但我不确定如何将其扩展为使用多封电子邮件：

session.query(Department).filter(
    Employee.email_address==request.args['email']
).outerjoin((Employee, Department.employees))

Answer 1

您可以使用any（）方法的关系。这段代码应该这样做：

session.query(Department).filter(
    Employee.email_address.any(value=request.args['email'])
).outerjoin((Employee, Department.employees))

Answer 2

你可以使用这样的任何（）：

department1 = Department()
department2 = Department()
DBSession.add(department1)
DBSession.add(department2)
employee = Employee()
employee.email_addresses.append(EmailAddress(employee.id, 'e@mail.com'))
DBSession.add(employee)
department1.employees.append(employee)
DBSession.flush() 
print(DBSession.query(Department).filter(Department.employees.any(Employee.email_addresses.any(EmailAddress.value == 'e@mail.com'))).all())

请参阅this gist以获取完整示例。

与contains（）的两级深度一对多关系

2 个答案: