[Sqlalchemy-tickets] [sqlalchemy] #2330: with_only_columns([func.count('*')]) works wrong in sqalchemy 0.7.3

[sqlalchemy <mi...@zz...>]

#2330: with_only_columns([func.count('*')]) works wrong in sqalchemy 0.7.3
--------------------+-------------------------------------------------------
 Reporter:  guest   |          Owner:  zzzeek                
     Type:  defect  |         Status:  new                   
 Priority:  medium  |      Milestone:                        
Component:  sql     |       Severity:  no triage selected yet
 Keywords:          |   Status_field:  awaiting triage       
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 query.with_only_columns([func.count('*')]) seems to produce invalid SQL
 since slqalchemy 0.7.3 (tested on fresh clone from hg too)

 code to reproduce it(tested also on mysql - the same issue):
 {{{
 from sqlalchemy import ForeignKey, create_engine, select, func
 from sqlalchemy.orm import sessionmaker, relationship
 from sqlalchemy.ext.declarative import declarative_base
 from sqlalchemy import Column, Integer, DateTime, Unicode


 Base = declarative_base()
 engine = create_engine('sqlite://', echo=False)
 Session = sessionmaker(autoflush=False, bind=engine)

 class Foo(Base):
     __tablename__ = 'foos'
     id = Column(Integer(), primary_key=True)
     xxx = Column(Unicode(10), nullable=False, default=u'xxx')

 session = Session()
 Base.metadata.create_all(engine)

 session.add_all(Foo() for _ in xrange(30))
 session.commit()

 foos_table = Foo.__table__

 query = select([foos_table])

 # doesn't work:/ (query: SELECT count(?) AS count_1)
 count = query.with_only_columns([func.count('*')])
 # wrong result: 1
 print '\tcount *: %i' % session.execute(count).scalar()

 # work (query: SELECT count(foos.id) AS count_1 FROM foos)
 count = query.with_only_columns([func.count(foos_table.c.id)])
 # correct result: 30
 print '\tcount id: %i' % session.execute(count).scalar()
 }}}

 test runs:

 sqlalchemy 0.7.3

 {{{
 $ python bug_with_only_columns.py
         count *: 1
         count id: 30
 }}}


 sqlalchemy 0.7.2

 {{{
 $ python bug_with_only_columns.py
         count *: 30
         count id: 30
 }}}

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Ticket URL: <http://www.sqlalchemy.org/trac/ticket/2330>
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