AttributeError when sqlalchemy model has field created by column_property

[phaethon]

I have a model, which includes column_property

class User(Base):
  name = Column(Text)
  lastname = Column(Text)
  full_name = column_property(name + " " + lastname)

When I start application I get this stack trace:

...
  File "/home/myhome/strawberry-test/lib/python3.10/site-packages/strawberry_sqlalchemy_mapper/mapper.py", line 371, in _convert_column_to_strawberry_type
    if column.nullable:
  File "/home/myhome/strawberry-test/lib/python3.10/site-packages/sqlalchemy/sql/elements.py", line 1495, in __getattr__
    raise AttributeError(
AttributeError: Neither 'Label' object nor 'Comparator' object has an attribute 'nullable'

If I comment out the full_name field in the model, it works as expected.

Ubuntu 22.04, python 3.10, SQLAlchemy 2.027, psycopg 3.1.18, strawberry-sqlalchemy-mapper 0.4.2, strawberry-graphql 0.219.2

[fruitymedley]

This appears to be an issue with column_property not having a nullable property. Specifically, line 369 is raising an exception. There appears to be an open issue to add Nullable to column_property in this sqlalchemy issue.

In the meantime, there are a few plausible workarounds, as I've also run into this issue.

1. Assume type_annotations without the nullable property are not nullable. This would cause issues in the case that the value is, in fact nullable.
2. Assume type_annotations without the nullable property are nullable. This would result in possibly misleading type annotations, and require additional null checking on the part of implementer.

Otherwise, I'm afraid we're held up by the former sqlalchemy issue.