Re: [SQLObject] fetch instance using column other than ID

[Ian B. <ia...@co...>]

On Mar 11, 2004, at 1:19 AM, charles brandt wrote:
> Sorry for the newbie question, but I'm having a hard time finding the 
> right
> way to fetch an existing class instance using a different column than 
> id.
> Assuming the example Person class with an added "email = StringCol()", 
> I am
> able to fetch based on the email using something like:
>
> user = Person.select(Person.q.email=="ab...@xy...", 
> connection=req.conn)[0]
>
> but that seems rather unintuitive compared to Person(10) (or 
> Person.get(10)
> now).  I think I'm envisioning an overridden _init  but the magic of 
> the
> metaclass is confusing me on how to implement it.  I was also thinking
> something along the lines of a class function (ie
> user=Person.lookup("ab...@xy...", req.conn) ) would be nice, but since 
> it is
> actually being initialized I don't think this is correct.
>
> Any ideas/comments?  Thanks in advance...

class Person(SQLObject):
     email = StringCol(alternateID=True)

user = Person.byEmail("ab...@xy...")

Or just:

user = Person.select(email="ab...@xy...")[0]

Or:

class Person(SQLObject):
     def lookup(cls, email, connection=None):
         return cls.select(email=email, connection=connection)[0]
     lookup = classmethod(lookup)

--
Ian Bicking | ia...@co... | http://blog.ianbicking.org