yeah with text just say "as sometable_somecolumn".
On Feb 27, 2007, at 4:16 PM, Dennis wrote:
>
> Well, columnname isn't a simple column in the case of a case
> statement... the label is turning out like this:
>
> "casewhenhas_testtrueandscoreisnullandgender1then1whenscoreisnullthen2
> elsescoreend"
>
> I haven't found a way to manually assign a label to a text clause yet,
> but before I tried use_labels=True, I has appended "as score" to the
> case clause and that worked.
>
> On Feb 27, 2:44 pm, Michael Bayer <[EMAIL PROTECTED]> wrote:
>> the label is always "tablename_columnname". youd have to show me
>> where you need that to be "programmatic".
>>
>> On Feb 27, 2007, at 2:29 PM, Dennis wrote:
>>
>>
>>
>>> Thanks for taking a peek.
>>
>>> Interesting, it does indeed fix the issue to use labels. Now I have
>>> another issue though, I have a case statement in my select which
>>> I was
>>> specifying like this:
>>
>>> select ( ['case when .... yada yada yada end as something' ] ......
>>
>>> If use_labels = True, then the query breaks because the generated
>>> sql
>>> has two as label parts two it.
>>
>>> if I delete the "as something" part, I think don't know
>>> programatically what the label is though. I need to know that
>>> because
>>> I order by it.
>>
>>> Isn't there a way to find out a column label from a query?
>>
>>> -Dennis
>>
>>> On Feb 27, 12:47 pm, Michael Bayer <[EMAIL PROTECTED]> wrote:
>>>> if you run it with full blown logging on, i.e.:
>>
>>>> import logging
>>>> logging.basicConfig()
>>>> logging.getLogger('sqlalchemy.engine').setLevel(logging.DEBUG)
>>>> logging.getLogger('sqlalchemy.orm').setLevel(logging.DEBUG)
>>
>>>> the issue can be detected when you look at the mapper creating
>>>> instance keys for "T" (although this is clearly not a novice
>>>> issue):
>>
>>>> DEBUG:sqlalchemy.orm.mapper.Mapper:(T|ts) _instance(): identity key
>>>> (<class '__main__.T'>, (1,), None) not in session[]
>>>> DEBUG:sqlalchemy.orm.mapper.Mapper:(T|ts) _instance(): identity key
>>>> (<class '__main__.T'>, (None,), None) not in session[]
>>>> DEBUG:sqlalchemy.orm.mapper.Mapper:(T|ts) _instance(): identity key
>>>> (<class '__main__.T'>, (3,), None) not in session[]
>>>> DEBUG:sqlalchemy.orm.mapper.Mapper:(T|ts) _instance(): identity key
>>>> (<class '__main__.T'>, (None,), None) not in session[]
>>>> DEBUG:sqlalchemy.orm.mapper.Mapper:(T|ts) _instance(): identity key
>>>> (<class '__main__.T'>, (5,), None) not in session[]
>>
>>>> so its not getting an identity key for every other row, which
>>>> indicates its looking at the wrong column in the result set. (on
>>>> each of those "None"s, its going to skip that entity) looking at
>>>> the
>>>> query:
>>
>>>> SELECT ts.id, ts.dat, other.ts_id, other.other_dat
>>>> FROM ts LEFT OUTER JOIN other ON ts.id = other.ts_id
>>
>>>> we can see that "other" has a column called "ts_id", which looks
>>>> exactly like the label that would be made for "id" in table
>>>> "ts". so
>>>> thats whats happening here. so throwing on a "use_labels=True" to
>>>> the query (or changing the name of "ts_id") produces the query:
>>
>>>> SELECT ts.id AS ts_id, ts.dat AS ts_dat, other.ts_id AS
>>>> other_ts_id,
>>>> other.other_dat AS other_other_dat
>>>> FROM ts LEFT OUTER JOIN other ON ts.id = other.ts_id
>>
>>>> that gives the correct results.
>>
>>>> not sure what SA can really do here to make this kind of issue
>>>> easier
>>>> to catch, since the resultproxy itself is where its looking for
>>>> "col
>>>> label, col name, ", etc. the generated labels are generally more
>>>> accurate. i tried playing around with ResultProxy to make it
>>>> detect
>>>> an ambiguity of this nature, but i think it might not be possible
>>>> unless more flags/switches get passed from the statement to the
>>>> result (which id rather not do since it further marginalizes
>>>> straight
>>>> textual queries), since if the select statement uses table/col
>>>> labels
>>>> for each column, there still could be conflicts which dont matter,
>>>> such as the column names the normal eager loader generates:
>>
>>>> 'ts_id', 'ts_dat', 'other_4966_ts_id', 'other_4966_other_dat',
>>
>>>> that result is from column "ts_id" attached to an Alias
>>>> "other_4966". if we said "dont allow any Column to be found
>>>> twice in
>>>> the row", then that breaks (since it will match other_4966_ts_id on
>>>> its _label, ts_id on its name).
>>
>>>> On Feb 27, 2007, at 12:09 PM, Dennis Muhlestein wrote:
>>
>>>>> from sqlalchemy import *
>>
>>>>> e=create_engine('sqlite://memory')
>>>>> ts=Table('ts',e,
>>>>> Column ( 'id',Integer,primary_key=True),
>>>>> Column ( 'dat',Integer,nullable=False))
>>>>> ts.create()
>>
>>>>> to_oneornone=Table('other',e,
>>>>> Column ( 'ts_id', Integer,ForeignKey('ts.id'),
>>>>> primary_key=True,
>>>>> nullable=False ),
>>>>> Column ( 'other_dat', Integer, nullable=False ) )
>>>>> to_oneornone.create()
>>
>>>>> class T(object): pass
>>>>> T.mapper=mapper(T,ts)
>>
>>>>> class To(object):pass
>>>>> To.mapper=mapper(To,to_oneornone,properties={'ts':relation
>>>>> (T,backref=backref('other',uselist=False))})
>>
>>>>> s=create_session()
>>>>> for x in range(10):
>>>>> t=T()
>>>>> t.dat=x
>>>>> s.save(t)
>>
>>>>> if x % 2 == 0: # test every other T has an optional data
>>>>> o=To()
>>>>> o.other_dat=x
>>>>> t.other=o
>>
>>>>> s.save(t)
>>>>> s.flush()
>>
>>>>> s.clear()
>>
>>>>> somedata=s.query(T).options(eagerload('other')).select()
>>>>> print 'Number results should be 10: ', len(somedata)
>>
>>>>> s.clear()
>>
>>>>> sel=select([ts,to_oneornone],
>>>>> from_obj=[ts.outerjoin(to_oneornone)])
>>
>>>>> print "Raw select also is 10: " , len(sel.execute().fetchall() )
>>
>>>>> print "Instances should also be 10: ", len(s.query(T).options
>>>>> (contains_eager('other')).instances(sel.execute()))
>
>
> >
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