It works! :) Now I can do this:
model.Resource.query.filter(model.Resource.parent ==
... model.Resource.query.filter_by(url='example.com').one()).one()
Resource at 'example.com/mypage'
Just so people know how to fix this if they have the same problem,
here is my mapper code, using SQLAlchemy
I just upgraded to 0.4.2, and tried to take advantage of the fix
available, but I'm confused. I have this code:
mapper(Resource, resources,
polymorphic_on=resources.c.type,
polymorphic_identity=empty,
column_prefix='_',
properties={
'id': resources.c.id,
'url':
map_column is shorthand for this:
table = Table('sometable', metadata,
...
Column('somecolumn', ...)
)
mapper(Class, table, properties= {
'_somecolumn':table.c.somecolumn,
'somecolumn':synonym('_somecolumn')
})
so the argument does not apply to your parent relation
in the case of parent, what happens if you just dont use a
synonym ? if it works then, there might be some silliness occuring
when backrefs get set up. the synonym for relation() is only
important if youre really looking for the extra querying attributes on
parent. you might also try
I don't know if I'm too clear, but I'll try to explain it. I'm using a
set up similar to the one in
http://www.sqlalchemy.org/docs/04/mappers.html#advdatamapping_mapper_inheritance_joined
. I want to be able to change the type of an object. For example, in
the example in the link above, I want to
Thanks, I will use the approach you describe here when I get to that
point in the development proccess :).
So for now, your best bet is to issue the SQL directly to the database
for the particular class change you want to do, remove the objects in
question from the session using expunge(),
On Dec 22, 5:07 pm, Michael Bayer [EMAIL PROTECTED] wrote:
a synonym() is used so that your attributes are properly available in
filter(). This functionality has been vastly improved in the current
SVN trunk which resolves all the issues you outline above, and will be
available in release
