On Apr 2, 2014, at 5:10 PM, Rob Crowell <rob.crow...@moat.com> wrote:
> I'm using the ORM and one of my tables does not have a primary key defined.
> I am also using DeferredReflection, and I can't seem to figure out how to
> defer the PrimaryKeyConstraint until Base.prepare() runs. Any pointers?
>
> Base = declarative_base(cls=DeferredReflection)
>
> class Person(Base):
> __tablename__ = 'people'
> __table_args__ = (PrimaryKeyConstraint(u'name'), {})
>
> # this does not run
> if __name__ == '__main__':
> engine = create_engine('mysql://user:password@localhost/organisms')
> Base.prepare(engine)
that form might be nice to add but currently you need the column to be present:
class Person(Base):
__tablename__ = 'people'
name = Column(String(20))
__table_args__ = (PrimaryKeyConstraint(u'name'), {})
>
>
> When this runs, we get an error constructing the Person class (the __main__
> section is not hit). This makes sense given that we haven't reflected the
> table yet!
>
> Traceback (most recent call last):
> File "/home/ubuntu/deferred_reflection.py", line 10, in <module>
> class Person(Base):
> File
> "/usr/local/lib/python2.7/dist-packages/sqlalchemy/ext/declarative/api.py",
> line 53, in __init__
> _as_declarative(cls, classname, cls.__dict__)
> File
> "/usr/local/lib/python2.7/dist-packages/sqlalchemy/ext/declarative/base.py",
> line 251, in _as_declarative
> **table_kw)
> File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/sql/schema.py",
> line 350, in __new__
> table._init(name, metadata, *args, **kw)
> File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/sql/schema.py",
> line 427, in _init
> self._init_items(*args)
> File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/sql/schema.py",
> line 70, in _init_items
> item._set_parent_with_dispatch(self)
> File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/sql/base.py", line
> 283, in _set_parent_with_dispatch
> self._set_parent(parent)
> File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/sql/schema.py",
> line 2646, in _set_parent
> super(PrimaryKeyConstraint, self)._set_parent(table)
> File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/sql/schema.py",
> line 2289, in _set_parent
> ColumnCollectionMixin._set_parent(self, table)
> File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/sql/schema.py",
> line 2257, in _set_parent
> col = table.c[col]
> File
> "/usr/local/lib/python2.7/dist-packages/sqlalchemy/util/_collections.py",
> line 156, in __getitem__
> return self._data[key]
> KeyError: u'name'
>
> --
> You received this message because you are subscribed to the Google Groups
> "sqlalchemy" group.
> To unsubscribe from this group and stop receiving emails from it, send an
> email to sqlalchemy+unsubscr...@googlegroups.com.
> To post to this group, send email to sqlalchemy@googlegroups.com.
> Visit this group at http://groups.google.com/group/sqlalchemy.
> For more options, visit https://groups.google.com/d/optout.
--
You received this message because you are subscribed to the Google Groups
"sqlalchemy" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to sqlalchemy+unsubscr...@googlegroups.com.
To post to this group, send email to sqlalchemy@googlegroups.com.
Visit this group at http://groups.google.com/group/sqlalchemy.
For more options, visit https://groups.google.com/d/optout.
