I have a legacy MySQL database that I am working with sqla version 1.0.11
and MySQL-Python engine (just upgraded to 1.0.14, problem persists)
I use automap_base and prepare with reflect=True
some of the tables in this database are association tables. Those tables
do show up in metadata, e.g.
In [74]: Base.metadata.tables['TripManifests']
> Out[74]: Table('TripManifests', MetaData(bind=None), Column('trip_id',
> INTEGER(display_width=11), ForeignKey(u'Trips.id'), table=<TripManifests>,
> nullable=False), Column('manifest_id', INTEGER(display_width=11),
> table=<TripManifests>, nullable=False), schema=None)
But the table isn't in Base.classes
In [75]: Base.classes.TripManifests
> AttributeError: TripManifests
The TripManifests table joins the Manifests table to the Trips table,
neither of which appear to show a fk to each or nor the TripManifests Table
In [80]: Base.metadata.tables['Trips'].foreign_keys
> Out[80]: {ForeignKey(u'Users.id'), ForeignKey(u'TripStatuses.id')}
> In [81]: Base.metadata.tables['Manifests'].foreign_keys
> Out[81]:
> {ForeignKey(u'Users.id'),
> ForeignKey(u'People.id'),
> ForeignKey(u'Lists.id'),
> ForeignKey(u'Equipment.id'),
> ForeignKey(u'Equipment.id')}
Since TripManifests is not Base.classes I'm not sure how to create an ORM
query using joins. I'd be ok with manually specifying the .join()
conditions if that would work, but I haven't seen an example of doing that
w/o using Base.classes
Alternatively I could try manually adding this class to Base but I haven't
been able to get that to work, does that need to be done before or after
prepare(reflect=True)?
Ultimately I would like to get away from using reflection. Does anyone know
of a tool that can reflect and then generate the declarative classes and
relationships as Python source.. which I could then hand-edit.
Moving forward I could then use alembic to manage the DB schema.. Though it
looks like adding a column would require that I use alembic to update the
database itself, then I'd still have to edit the Python declaration as well
(assuming I didn't want to use reflection), but that's a different
discussion.
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