So I managed to get something to return using this definition of the
@expression, however, I'm not quite there yet.
@hybrid_property
def restwave(self):
if self.target:
redshift = self.target.NSA_objects[0].z
wave = np.array(self.wavelength.wavelength)
restwave = wave/(1+redshift)
return restwave
else:
return None
@restwave.expression
def restwave(cls):
session = db.Session()
nsaz = session.query(sampledb.NSA.z.label('z')).\
join(sampledb.MangaTargetToNSA, sampledb.MangaTarget, Cube).\
filter(Cube.mangaid == cls.mangaid).subquery('nsaz', with_labels
=True)
unwave = session.query((func.unnest(Wavelength.wavelength)/(1+nsaz.c
.z)).label('restw')).subquery('unwave', with_labels=True)
restwave = session.query(func.array_agg(unwave.c.restw)).as_scalar()
return restwave
Using the example query,
rwquery = session.query(datadb.Cube.restwave).filter(datadb.Cube.mangaid==
'1-113520')
rw = rwquery.first()
I am getting a modified wavelength array, but it's the wrong one, using the
wrong ID. For the ID 1-113520 I should be modifying the wavelength array
by (1+0.016765) and instead it's just grabbing the very first value in the
NSA.z column, which corresponds to (1+0.099954). I think this is because
my filter condition is not getting passed into the nsaz subquery, where it
needs to go. Do you know how I can pass filter condition parameters down
into any subqueries I may have in me expression select statements? Is that
what .correlate() does?
My query looks like
In [24]: print rwquery
SELECT (SELECT array_agg(unwave.restw) AS array_agg_1
FROM (SELECT unnest(mangadatadb.wavelength.wavelength) / (%(z_1)s + nsaz.z)
AS restw
FROM mangadatadb.wavelength, (SELECT mangasampledb.nsa.z AS z
FROM mangasampledb.nsa JOIN mangasampledb.manga_target_to_nsa ON
mangasampledb.nsa.pk = mangasampledb.manga_target_to_nsa.nsa_pk JOIN
mangasampledb.manga_target ON mangasampledb.manga_target.pk = mangasampledb.
manga_target_to_nsa.manga_target_pk JOIN mangadatadb.cube ON mangasampledb.
manga_target.pk = mangadatadb.cube.manga_target_pk
WHERE mangadatadb.cube.mangaid = mangadatadb.cube.mangaid) AS nsaz) AS
unwave) AS anon_1
FROM mangadatadb.cube
WHERE mangadatadb.cube.mangaid = %(mangaid_1)s
--
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.
