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POsqlalchemy does not enforce foreign key constraing
 

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    <p>I am trying to play with the sql alchemy ORM based db definition. I have defined my tables as follows</p> <pre><code>class Customer(Base): __tablename__ = 'customer' id = Column(Integer, primary_key=True) name = Column(String(80)) auth = relationship("CustomerAuth", backref='customer') class CustomerAuth(Base): __tablename__ = 'authentication' id = Column(Integer, ForeignKey('customer.id')) username = Column(String(80), primary_key=True) passwd = Column(String(80)) </code></pre> <p>Now I am creating the session</p> <pre><code>Session = sessionmaker(bind=sqla.engine) session = Session() </code></pre> <p>And then I try to create two row objects for Customer with id 1 and 2</p> <pre><code>cst1 = sqla.Customer(id=1,name='shyam') cst2 = sqla.Customer(id=2,name='ram') </code></pre> <p>And I create three row objects for CustomerAuth which reference to id 1, 2 and 3 of Customer</p> <pre><code>auth1 = sqla.CustomerAuth(id=1,username='shyamu',passwd='wam') auth2 = sqla.CustomerAuth(id=2,username='ramu',passwd='dam') auth3 = sqla.CustomerAuth(id=3,username='lamu',passwd='sam') </code></pre> <p>As you can see I have created a CustomerAuth row with id = 3 , which is a foreign key referring the Customer.id. But since Customer table has no entry with id=3 , this should fail</p> <pre><code>session.add(cst1) session.add(cst2) session.add(auth1) session.add(auth2) session.flush() </code></pre> <p>This operation should fail but it goes through successfully.</p> <pre><code>session.add(auth3) session.flush() </code></pre> <p>I want to know what am I not doing which bypasses the foreign key enforcement</p> <p>Thanks in advance</p>
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    1. USShyam
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    1. COWhat RSBMS are you using? MySQL with MyISAM tables?
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      1. USJoachim Isaksson
    2. COi am using sqlite. I am creating an in memory sqlite db as follows ----- from sqlalchemy import create_engine engine = create_engine('sqlite:///:memory:', echo=True)
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