On Nov 17, 2010, at 9:07 AM, Adrien Saladin wrote:
> On Wed, Nov 17, 2010 at 1:16 AM, Michael Bayer <[email protected]>
> wrote:
>> ForeignKeyConstraint needs to go into __table_args__ when using declarative.
>>
>> http://www.sqlalchemy.org/docs/orm/extensions/declarative.html#table-configuration
>
> Thanks for the note. I have updated my test script to use
> __table_args__ but the error remains the same (see script and ouput
> below).
OK its actually a huge SQLA bug that an error isn't raised for that, which is
surprising to me, so I created and resolved #1972 in r67d8f4e2fcb9.
__table_args__ is expected to be a tuple or dict, so now an error is raised if
it's not. (x) isn't a tuple.
here's the correct form:
class Bar(Base):
__tablename__ = "bar"
__table_args__ = ( ForeignKeyConstraint(['one_id', 'two_id'], ['foo.one',
'foo.two']),{} )
id = Column(Integer, primary_key=True)
one_id = Column(Integer, nullable=False)
two_id = Column(Integer, nullable=False)
foo = relationship("Foo", backref = "bars")
>
> I then tried with the hybrid approach
> (http://www.sqlalchemy.org/docs/orm/extensions/declarative.html#using-a-hybrid-approach-with-table)
> which works well.
> Am I again doing something wrong with declarative ?
>
> Thanks,
>
>
> #################################
> from sqlalchemy import *
> from sqlalchemy.orm import *
> from sqlalchemy.ext.declarative import declarative_base
>
>
> Base = declarative_base()
>
> class Foo(Base):
> __tablename__ = "foo"
> one = Column(Integer, primary_key=True)
> two = Column(Integer, primary_key=True)
>
> class Bar(Base):
> __tablename__ = "bar"
> __table_args__ = ( ForeignKeyConstraint(['one_id', 'two_id'],
> ['foo.one', 'foo.two']) )
> id = Column(Integer, primary_key=True)
> one_id = Column(Integer, nullable=False)
> two_id = Column(Integer, nullable=False)
>
> foo = relationship("Foo", backref = "bars")
>
>
>
> metadata = Base.metadata
>
> engine = create_engine('sqlite:///:memory:', echo=True)
> metadata.create_all(engine)
>
> from sqlalchemy.orm import sessionmaker
>
> # create a configured "Session" class
> Session = sessionmaker(bind=engine)
>
> # create a Session
> session = Session()
>
> foo = Foo()
> foo.one = 1
> foo.two = 2
> session.add(foo)
> session.commit()
>
> #############################
>
>
>
> 2010-11-17 14:56:01,309 INFO sqlalchemy.engine.base.Engine.0x...9690
> PRAGMA table_info("foo")
> 2010-11-17 14:56:01,309 INFO sqlalchemy.engine.base.Engine.0x...9690 ()
> 2010-11-17 14:56:01,310 INFO sqlalchemy.engine.base.Engine.0x...9690
> PRAGMA table_info("bar")
> 2010-11-17 14:56:01,310 INFO sqlalchemy.engine.base.Engine.0x...9690 ()
> 2010-11-17 14:56:01,310 INFO sqlalchemy.engine.base.Engine.0x...9690
> CREATE TABLE foo (
> one INTEGER NOT NULL,
> two INTEGER NOT NULL,
> PRIMARY KEY (one, two)
> )
>
>
> 2010-11-17 14:56:01,310 INFO sqlalchemy.engine.base.Engine.0x...9690 ()
> 2010-11-17 14:56:01,310 INFO sqlalchemy.engine.base.Engine.0x...9690 COMMIT
> 2010-11-17 14:56:01,311 INFO sqlalchemy.engine.base.Engine.0x...9690
> CREATE TABLE bar (
> id INTEGER NOT NULL,
> one_id INTEGER NOT NULL,
> two_id INTEGER NOT NULL,
> PRIMARY KEY (id)
> )
>
>
> 2010-11-17 14:56:01,311 INFO sqlalchemy.engine.base.Engine.0x...9690 ()
> 2010-11-17 14:56:01,311 INFO sqlalchemy.engine.base.Engine.0x...9690 COMMIT
> Traceback (most recent call last):
> File "compositePrimaryKey_decl.py", line 39, in <module>
> foo = Foo()
> File "<string>", line 4, in __init__
> File
> "/home/virtualenvs/sqlalchemy/lib/python2.6/site-packages/sqlalchemy/orm/state.py",
> line 93, in initialize_instance
> fn(self, instance, args, kwargs)
> File
> "/home/virtualenvs/sqlalchemy/lib/python2.6/site-packages/sqlalchemy/orm/mapper.py",
> line 2357, in _event_on_init
> instrumenting_mapper.compile()
> File
> "/home/virtualenvs/sqlalchemy/lib/python2.6/site-packages/sqlalchemy/orm/mapper.py",
> line 805, in compile
> mapper._post_configure_properties()
> File
> "/home/virtualenvs/sqlalchemy/lib/python2.6/site-packages/sqlalchemy/orm/mapper.py",
> line 834, in _post_configure_properties
> prop.init()
> File
> "/home/virtualenvs/sqlalchemy/lib/python2.6/site-packages/sqlalchemy/orm/interfaces.py",
> line 493, in init
> self.do_init()
> File
> "/home/virtualenvs/sqlalchemy/lib/python2.6/site-packages/sqlalchemy/orm/properties.py",
> line 840, in do_init
> self._determine_joins()
> File
> "/home/virtualenvs/sqlalchemy/lib/python2.6/site-packages/sqlalchemy/orm/properties.py",
> line 969, in _determine_joins
> % self)
> sqlalchemy.exc.ArgumentError: Could not determine join condition
> between parent/child tables on relationship Bar.foo. Specify a
> 'primaryjoin' expression. If this is a many-to-many relationship,
> 'secondaryjoin' is needed as well.
>
>
> The script below works with the hybrid declarative approach:
>
> #################################
> from sqlalchemy import *
> from sqlalchemy.orm import *
> from sqlalchemy.ext.declarative import declarative_base
>
>
> Base = declarative_base()
>
> class Foo(Base):
> __tablename__ = "foo"
> one = Column(Integer, primary_key=True)
> two = Column(Integer, primary_key=True)
>
>
>
> bartable = Table("bar", Base.metadata,
> Column("id", Integer, primary_key=True),
> Column("one_id", Integer, nullable=False),
> Column("two_id", Integer, nullable=False),
> ForeignKeyConstraint(['one_id', 'two_id'], ['foo.one', 'foo.two']),
> )
>
>
>
>
> class Bar(Base):
> __table__ = bartable
> foo = relationship("Foo", backref = "bars")
>
>
> metadata = Base.metadata
>
> engine = create_engine('sqlite:///:memory:', echo=True)
> metadata.create_all(engine)
>
> from sqlalchemy.orm import sessionmaker
>
> # create a configured "Session" class
> Session = sessionmaker(bind=engine)
>
> # create a Session
> session = Session()
>
> foo = Foo()
> foo.one = 1
> foo.two = 2
> session.add(foo)
> session.commit()
>
>
> bar = Bar()
> bar.foo = foo
> session.add(bar)
>
>
> session.commit()
>
>
> #############################
>
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