On Feb 28, 2014, at 2:12 PM, Jonathan Vanasco <jonat...@findmeon.com> wrote:
> > > On Friday, February 28, 2014 12:41:46 PM UTC-5, Michael Bayer wrote: > > nope. get() means, “the SELECT may not happen”. eager loads are always > secondary to the fact that the row is being loaded. if you want to > definitely load the row, say filter_by(id…).first(). > > Poking at the source this may sort of do most of what you want if you say > query.populate_existing().get(1). the components to make this operation > occur are there but they aren’t put together into a tested API (test coverage > and documentation are the main things that make it slow to add things like > this officially). > > Boo. > > I have an "internal api" that handles most ( soon to be all ) the SqlAlchemy > management. With the amount of code we have right now, it was the best way > to minimize and manage the impact of constantly evolving changes to the > schema or product requiresments. > > There are times we want to use `filter()`, but for a handful of things -- > namely calculating Permissions/Authentication for ACLs -- we're switching to > use `get()`. I only want to hit the DB once on these. The queries are > dynamically generated; most don't have eagerloads. some do. > > .populate_existing will re-fetch the item, no matter what. I don't want to > re-fetch the 'core' table if it is already loaded; I just want to fetch the > misc attributes if they haven't been loaded yet. > > i'll just 'touch' the properties in my code if they're needed after the > 'get'. that will load them. OK well it has to emit the SELECT for the primary row, but yes populate_existing will overwrite, so really, just any equivalent of query(User).filter_by(primary key).first() is really all you need here…we used to have a load() method that did this but it fell out of repair and nobody missed when i removed it, wasn’t worth maintaining. The internal stuff used by get() in the “loading” module can probably be worked to provide this feature similarly to how get() works.
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