[Sqlalchemy-tickets] Issue #3188: regression in 0.9's "order by collapse" logic (zzzeek/sqlalchemy)

[Mike B. <iss...@bi...>]

New issue 3188: regression in 0.9's "order by collapse" logic
https://bitbucket.org/zzzeek/sqlalchemy/issue/3188/regression-in-09s-order-by-collapse-logic

Mike Bayer:

seems to be non-deterministic


```
#!python

from sqlalchemy import *
from sqlalchemy.orm import *
from sqlalchemy.ext.declarative import declarative_base

Base = declarative_base()

class C(Base):
    __tablename__ = 'c'

    id = Column(Integer, primary_key=True)
    a_id = Column(ForeignKey('a.id'))
    b_id = Column(ForeignKey('b.id'))

class B(Base):
    __tablename__ = 'b'

    id = Column(Integer, primary_key=True)

B.b = column_property(
        select([func.max(C.id)]).where(C.b_id == B.id).correlate(B)
    )


b1 = aliased(B)

sess = Session()

#print sess.query(B, b1).order_by(B.b)
print sess.query(B, b1).order_by(b1.b)

```

output, based on if you uncomment that one query, for the *second* query, is:

```
#!sql


SELECT b.id AS b_id, (SELECT max(c.id) AS max_1 
FROM c 
WHERE c.b_id = b.id) AS anon_1, b_1.id AS b_1_id, (SELECT max(c.id) AS max_2 
FROM c 
WHERE c.b_id = b_1.id) AS anon_2 
FROM b, b AS b_1 ORDER BY anon_1
```

e.g. it is ordering by the wrong expression.

there's a lot going on with order_by right now so im not sure this can be in 0.9, will need to see if something can be backported.