On 12/01/2016 09:13 AM, Adrian wrote:
Is there any shorter/prettier way for this?
session.query(session.query(Foo).exists()).scalar()
I would normally do
session.query(Foo).count()
I've never embedded an EXISTS like that.
It's not hard to add a custom method to the base query class that returns
self.session.query(self.exists()).scalar()
how does this interact with filtering etc? seems like this method
would work just like count().
but it feels like something that should be part of SQLAlchemy.
Also, is there any case where `.enable_eagerloads(False)` right before
`.exists()` could cause problems / different results?
this query is against column expressions, not entities, so eager loading
is not involved.
If not, wouldn't it make sense for exists() to do that automatically?
Loading a relationship doesn't ever seem to make sense
when checking exists().
there's no entity loaded so relationships aren't involved.
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