Support self referential tables for SQLModels

[sheinbergon]

Changes

Add support for self-referential tables for SQLModels

For a tabe definition like

Table(
    "simple_items",
    generator.metadata,
    Column("id", INTEGER, primary_key=True),
    Column("parent_item_id", INTEGER, ForeignKey("simple_items.id")),
)

The generated output changes from:

sa_relationship_kwargs={'remote_side': [id]}

to:

sa_relationship_kwargs={'remote_side': '[SimpleItems.id]'}

Fixes #460

Checklist

If this is a user-facing code change, like a bugfix or a new feature, please ensure that
you've fulfilled the following conditions (where applicable):

• You've added tests (in tests/) which would fail without your patch
• You've added a new changelog entry (in CHANGES.rst).

[sheinbergon]

@agronholm coveralls is currently down, but tests are passing locally. It's ready for review

[agronholm]

I'll review this tomorrow.

[sheinbergon]

@StrikerRUS can you confirm the code on my branch addresses the errors you've encountered?

[agronholm]

Looks good now.

[StrikerRUS]

@sheinbergon Thanks a lot for the PR! Will check this weekend.

[StrikerRUS]

@sheinbergon
Just checked your branch - my initial example now works fine without errors. Thank you so much for prompt fix!

[sheinbergon]

@agronholm coveralls is still down (what a blunder), but test are passing locally. I'll take the liberty of merging this PR.

[agronholm]

The issue with the Coveralls site isn't even technical – it's an account issue with their infrastructure provider.

[baraknaveh]

Thanks for the fix!

[sheinbergon]

Thanks for the fix!

Ein ba'ad ma