[Sqlalchemy-tickets] [sqlalchemy] #2796: Labeled subqueries

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

#2796: Labeled subqueries
----------------------+-----------------------------------------
 Reporter:  kvesteri  |           Owner:  zzzeek
     Type:  defect    |          Status:  new
 Priority:  high      |       Milestone:
Component:  sql       |        Severity:  no triage selected yet
 Keywords:            |  Progress State:  awaiting triage
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 Atleast PostgreSQL requires aliases for all subqueries. I'm trying to
 formulate the following query into SQLAlchemy expression construct:

   {{{#!SQL
   SELECT count(DISTINCT :param_1) AS count_1
   FROM (
       SELECT company.id AS id
       FROM company
   ) AS company_ids
   }}}


 Now assume Company is any declarative class containing only one column
 (id).

   {{{#!python
   company_ids = db.select([Company.id], from_obj=Company.__table__)

   print db.session.execute(db.select([db.func.count(db.distinct('id'))],
 from_obj=company_ids.label('company_ids')))
   }}}

 It gives me the following exception:

 AttributeError: Neither 'Label' object nor 'Comparator' object has an
 attribute '_hide_froms'


 I know the query I provided here makes a little sense (it could be
 simplified to a query without subqueries). I provided it as an example of
 failing scenario.

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Ticket URL: <http://www.sqlalchemy.org/trac/ticket/2796>
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