Hi, so I have the database classes as follows:
class Thing(Base): DatasetId = Column(ForeignKey(schema +
'Dataset.DatasetId'), primary_key=True, nullable=False, index=True)
RequiredThing_child = relationship('RequiredThing', cascade='all,
delete-orphan') class Location(Base): DatasetId = Column(ForeignKey(schema
+ 'Dataset.DatasetId'), primary_key=True, nullable=False, index=True)
RequiredThing_child = relationship('RequiredThing', cascade='all,
delete-orphan') class RequiredThing(Base): DatasetId =
Column(ForeignKey(schema + 'Dataset.DatasetId'), primary_key=True,
nullable=False, index=True) Thing= relationship('Thing', viewonly=True)
Location= relationship('Location', viewonly=True)
(There are more relationships on both tables but these ones are the only
ones that I've had issues with, as they both have that column).
I set them up like that because I want to have the cascade deletion
functionality: whenever I call for a deletion of a thing object I want the
children (in this case RequiredThing) to be deleted as well (as long as it
matches with the Thing Id). When I had it active for only one table (in
this case Thing), it worked fine but now that I also added the relationship
for the Location table it's giving me the following warning: SAWarning:
relationship 'Location.RequiredThing_child' will copy column
Location.DatasetId to column RequiredThing.DatasetId, which conflicts with
relationship: 'Thing.RequiredThing_child' (copies Thing.DatasetId to
RequiredThing.DatasetId).
I've tried to add back_populates to the RequiredThing class but to no avail.
I need this to work because I want to implement the cascade functionality
to many more tables as needed but I do not want there to be any errors or
ambiguity when running the queries.
Or if there's a better way to implement cascade deletion I'm all for it.
Any suggestions or corrections to my code would be greatly appreciated!
Kind regards,
Javier
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