OK here we are, had to switch approaches due to a bug with the column reflect event, to use the aforementioned __mapper_cls__ (had the name wrong), so I think you'll see this is a pretty open-ended way to control how something maps as you're given total access to mapper() here:
from sqlalchemy import *
from sqlalchemy.orm import *
from sqlalchemy.ext.declarative import declarative_base, declared_attr
from sqlalchemy.ext.declarative import DeferredReflection
from sqlalchemy import event
Base = declarative_base()
e = create_engine("sqlite://", echo=True)
e.execute("""
create table sample (
Id integer primary key,
Name varchar,
Description varchar,
IsActive varchar
)
""")
class MagicMappyThing(DeferredReflection):
@declared_attr
def __mapper_cls__(cls):
def map_(cls, *arg, **kw):
props = kw.setdefault("properties", {})
for k, v in cls.__map__.items():
props[v] = cls.__table__.c[k]
return mapper(cls, *arg, **kw)
return map_
class Sample(MagicMappyThing, Base):
__tablename__ = 'sample'
__map__ = {'Id': 'id', 'Name': 'name', 'Description': 'description',
'IsActive': 'is_active'}
def __init__(self, id, name, description, is_active):
self.id = id
self.name = name
self.description = description
self.is_active = is_active
MagicMappyThing.prepare(e)
s = Session(e)
s.add(Sample(id=1, name='some name', description='foo', is_active='foo'))
s.commit()
On Aug 26, 2013, at 5:17 PM, Michael Bayer <mike...@zzzcomputing.com> wrote:
>
> On Aug 26, 2013, at 5:16 PM, Michael Bayer <mike...@zzzcomputing.com> wrote:
>
>>
>> On Aug 26, 2013, at 4:35 PM, Praveen <praveen.venk...@gmail.com> wrote:
>>
>>> The problem with using Mixins is that you need to know the definition of
>>> columns already for creating the mixin class. What I am trying to do is
>>> more like get the definition dynamically on the fly.Take a look at this:
>>
>> here's a simple way to add reflection events which intercept the Column and
>> add the .key of your choice, and saves on code by making use of the existing
>> DeferredReflection mixin instead of hand-coding it.
>
> except it doesnt work yet, give me 10 minutes.
>
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