Well, columnname isn't a simple column in the case of a case
statement... the label is turning out like this:
"casewhenhas_testtrueandscoreisnullandgender1then1whenscoreisnullthen2elsescoreend"
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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