Sort by relationship

[zolkos-ap]

Hi,
is it possible to sort a column by a relationship attribute?

My specific case:

class Project(Base):
    __tablename__ = 'projects'

    id = Column(UUID(as_uuid=True), nullable=False, primary_key=True, default=uuid.uuid4)
    name = Column(String, nullable=False, unique=True)

    categories = relationship("Category", back_populates="project")

    def __str__(self):
        return self.name

class Category(Base):
    __tablename__ = 'categories'

    id = Column(UUID(as_uuid=True), nullable=False, primary_key=True, default=uuid.uuid4)
    project_id = Column(UUID(as_uuid=True), ForeignKey("projects.id"), nullable=False)

    project = relationship("Project", back_populates="categories", foreign_keys="Category.project_id", lazy="selectin")

In my CategoryAdmin ModelView I have tried:

1. column_sortable_list = [Category.project] but get Mapped instance expected for relationship comparison to object. at runtime.
2. column_sortable_list = [Category.project.name] but get Neither 'InstrumentedAttribute' object nor 'Comparator' object associated with Category.project has an attribute 'name'

I have also defined a __str__ method for my Project class, But that didn't resolve this issue.
Is there any way I can make the Category.project column sortable?

[aminalaee]

Hey,

The first approach is not clear to me, how do you want to sort by Category.project? It should be with some attribute, right?

The second approach is not possible in SQLAlchemy, so you can't do:

column_sortable_list = [Category.project.name]

It should be supported with column_sortable_list = ["project.name"] but that's not available yet. Feel free to add this feature otherwise I'll get to it later.