Hy,
For a long time ago I manage versioned data's into relational
database. You must be careful with the way you deal with timeable
information.
Membership table represent information with a validity period
specified by start and stop attribute.
The first change that I propose is to replace your
Jess,
Thanks for posting the actual class :) Just reading the description
"use contains_eager" didn't tell me enough about how to make it
happen.
Cheers,
Gregg
On Thu, Jul 16, 2009 at 12:54 PM, jess wrote:
>
> I believe that I asked Michael a similar question, in a different way,
> a few days
I believe that I asked Michael a similar question, in a different way,
a few days ago.
The answer was to use "contains_eager". I used something like the
following and it worked great to query what the membership of a group
was at a specific time. The two tables remain simple, related by a
group
That's a totally fair answer! Mostly, I wish some sense of relational
change over time was built into SQL, the way it is in BigTable style
systems.
Maybe you could shed a little light on how to use the overlap
operator? I'm having trouble getting the multiple fields into the
clause statement.
I
Gregg Lind wrote:
>
> Questions:
>
>
> 1. Is there a "SQLAlchemical" way to write group_snapshot_ts into
> a declarative class, such that the joins and loader respect the
> time
> constraints? (Read-only is fine as well on the loaded attributes)
> a. eager_loader?
> b. subclass
