Boolean-typed column_property test case

import sqlalchemy as sa
from sqlalchemy import orm
from sqlalchemy.ext.declarative import declarative_base

Base = declarative_base()

class Parent(Base):
    __tablename__ = "parent"

    id = sa.Column(sa.Integer, primary_key=True)
    expr = orm.column_property(id > 0)

    children = orm.relationship("Child", back_populates="parent")

class Child(Base):
    __tablename__ = "child"

    id = sa.Column(sa.Integer, primary_key=True)
    parent_id = sa.Column(sa.Integer, sa.ForeignKey("parent.id"))

    parent = orm.relationship("Parent", back_populates="children")

engine = sa.create_engine("postgres:///test", echo=True)
Base.metadata.create_all(engine)

session = orm.Session(bind=engine)
q = session.query(Parent)
q = q.options(orm.joinedload(Parent.children))
q = q.order_by(Parent.expr)
# Workaround:
#q = q.order_by(sa.case([(Parent.expr, 1)], else_=0))
q = q.limit(10)
q.all()