Support complex joins

[alonroth]

Hi,

First of all, thanks for this library, it's been making our life much easier so far while working with GraphQL (Graphene).

I was wondering why this library doesn't support complex joins.

I was able to allow it pretty fast - and I was wondering what I'm missing here - I was just adding the following:

        if hasattr(self.parent_property.primaryjoin, 'clauses'):
            q = q.filter(
                *self.parent_property.primaryjoin.clauses
            )

after:
q = q.filter(self._join_col.in_(param_values))

Thanks

[chanind]

That seems reasonable to me. Want to open up a PR with this feature?

[Adarsh-Roy]

This works, but we will have to bypass the validation of relations with something similar to

    def _validate_relation(self):
        criterion, param_keys = self._simple_lazy_clause
        if hasattr(self.parent_property, 'primaryjoin'):
            # Allow complex joins
            return

I'm not sure if that will create some other problems though ?