Impossible to generate schema with classes only (opposite of --noclasses) about sqlacodegen

[agronholm]

SQLAlchemy ORM classes do not work without a primary key definition: https://docs.sqlalchemy.org/en/14/faq/ormconfiguration.html#how-do-i-map-a-table-that-has-no-primary-key
You do know that you can use a Session to query plain tables too?

[agronholm]

For what purpose would you want association tables to be classes instead of interim tables in many-to-many relationships? As for the other case, tables without a pk column cannot be classes anyway.

[thirdeye-hichame]

@agronholm , thanks for the response. I wanted to generate classes similar to here

Since it was 5 months ago I don't have the exact specific use case any more but I know I wanted to insert objects into an interim table with a composite primary key PRIMARY KEY(parent_id, children_id)

To solve this problem I forked agronholm/sqlacodegen and added the argument myself.

[agronholm]

I guess I could add something like --nomanytomany which would skip the detection of association tables, in which case they would be rendered as classes instead of Tables (assuming they have primary keys). Would this be acceptable?

[petergok]

This would be very useful for us to be able to generate classes we can query for tables that don't have a primary key. Here's a quick proposed solution with an --onlyclasses argument: https://github.com/perpetua1/sqlacodegen

[petergok]

You're right, we just tried it and it didn't work with class-based tables. The problem is that we recently removed the primary key and had a lot of code that accessed columns through Class.column rather than Class.c.column.

We'll see if we can get around this but this something within sqlalchemy itself rather than this library.