Ahh. Thanks. Here is the class side then. Still None.
In [14]: print datadb.Sample.nsa_logmstar
None
Brian
On Friday, January 15, 2016 at 8:48:30 AM UTC-5, Simon King wrote:
>
> "Sample()" is an instance. "Sample" is the class. Try:
>
> print datadb.Sample.nsa_logmstar
>
> Simon
>
> On Fri, Jan 15, 2016 at 1:46 PM, Brian Cherinka <havo...@gmail.com
> <javascript:>> wrote:
>
>> Hi Simon,
>>
>> Printing on the class side, I get
>>
>> In [11]: print datadb.Sample().nsa_logmstar
>> None
>>
>> It looks like it's getting set to None (or remaining None). I'm not
>> quite sure what this tells me, except that it's not working. Printing on
>> in the instance side, I get
>>
>> In [12]: print cube.sample[0].nsa_mstar
>> 1386160000.0
>>
>> In [13]: print cube.sample[0].nsa_logmstar
>> 9.14181336239
>>
>> nsa_mstar is a column in my database table, and nsa_logmstar I want to be
>> simply the log-base10 of that quantity.
>>
>> If this doesn't give any insight, then it will take me some time to
>> provide a small script. This code is embedded into a bunch of stuff. But
>> I'll work on it.
>>
>> Brian
>>
>>
>> On Friday, January 15, 2016 at 5:00:51 AM UTC-5, Simon King wrote:
>>
>>> On Fri, Jan 15, 2016 at 6:16 AM, Brian Cherinka <havo...@gmail.com>
>>> wrote:
>>>
>>>> I'm trying to set up a hybrid property / expression in a custom class,
>>>> that I can use in queries. I think I have the syntax correct, however the
>>>> query returns the entire table, instead of the correct subset of results.
>>>> And the where clause just indicates True rather than the correct
>>>> expression.
>>>>
>>>>
>>>> Here is my hybrid property/expression definition
>>>>
>>>> class Sample(Base,ArrayOps):
>>>> __tablename__ = 'sample'
>>>> __table_args__ = {'autoload' : True, 'schema' : 'datadb'}
>>>>
>>>> def __repr__(self):
>>>> return '<Sample (pk={0},cube={1})'.format(self.pk,self.cube)
>>>>
>>>> @hybrid_property
>>>> def nsa_logmstar(self):
>>>> try: return math.log10(self.nsa_mstar)
>>>> except ValueError as e:
>>>> return -9999.0
>>>> except TypeError as e:
>>>> return None
>>>>
>>>> @nsa_logmstar.expression
>>>> def nsa_logmstar(cls):
>>>> return func.log(cls.nsa_mstar)
>>>>
>>>> The session query is
>>>>
>>>> session.query(Sample.pk).filter(Sample.nsa_logmstar < 9)
>>>>
>>>> But printing it does not show the appropriate condition. I get
>>>>
>>>> SELECT datadb.sample.pk AS datadb_sample_pk,
>>>> FROM datadb.sample
>>>> WHERE true
>>>>
>>>> and the results return the entire table of ~11000 rows instead of the
>>>> expected 272 rows. What's going on here? Everything looks correct to me,
>>>> but I can't figure it out.
>>>>
>>>> I'm expecting the SQL statement to look like this
>>>>
>>>> select s.pk
>>>> from datadb.sample as s
>>>> where log(s.nsa_mstar) < 9;
>>>>
>>>> Any thoughts? Thanks.
>>>>
>>>>
>>> I can't see anything obviously wrong with your code, but it looks like
>>> Sample.nsa_logmstar is not actually resolving to the hybrid property in
>>> your query. What happens if you "print Sample.nsa_logmstar" just before the
>>> query?
>>>
>>> Otherwise, please provide a small runnable script that demonstrates the
>>> problem.
>>>
>>> Simon
>>>
>> --
>> You received this message because you are subscribed to the Google Groups
>> "sqlalchemy" group.
>> To unsubscribe from this group and stop receiving emails from it, send an
>> email to sqlalchemy+...@googlegroups.com <javascript:>.
>> To post to this group, send email to sqlal...@googlegroups.com
>> <javascript:>.
>> Visit this group at https://groups.google.com/group/sqlalchemy.
>> For more options, visit https://groups.google.com/d/optout.
>>
>
>
--
You received this message because you are subscribed to the Google Groups
"sqlalchemy" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to sqlalchemy+unsubscr...@googlegroups.com.
To post to this group, send email to sqlalchemy@googlegroups.com.
Visit this group at https://groups.google.com/group/sqlalchemy.
For more options, visit https://groups.google.com/d/optout.
