Re: [Sqlalchemy-tickets] [sqlalchemy] #2818: Query.exists() don't works with queries without filters

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

#2818: Query.exists() don't works with queries without filters
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      Reporter:  vmagamedov   |      Owner:  zzzeek
          Type:  defect       |     Status:  reopened
      Priority:  high         |  Milestone:  0.8.xx
     Component:  orm          |   Severity:  minor - half an hour
    Resolution:               |   Keywords:
Progress State:  in progress  |
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Changes (by zzzeek):

 * status:  closed => reopened
 * resolution:  fixed =>
 * status_field:  completed/closed => in progress


Comment:

 bit of a glitch:

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

 Base = declarative_base()

 class ModelBase(Base):
     __tablename__ = 'ModelBases'
     id = sa.Column(sa.Integer, primary_key=True)
     model_type = sa.Column(sa.Integer)
     __mapper_args__ = {'polymorphic_on': model_type}

 class Model(ModelBase):
     __tablename__ = 'Models'
     __mapper_args__ = {'polymorphic_identity': 1}
     id = sa.Column(sa.ForeignKey(ModelBase.id), primary_key=True)

 sess = sa.orm.Session()

 print sess.query(Model).exists()
 }}}

 generates a select columns warning because use_labels isn't set.

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Ticket URL: <http://www.sqlalchemy.org/trac/ticket/2818#comment:3>
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