On Thursday, September 4, 2014 2:19:34 PM UTC-4, Ofir Herzas wrote:
>
> Nevertheless, is there a way to achieve what I want? (which is to
> selectively load several columns and this 'jobs' property from Employee)
>
The ways I usually do that are:
1. Select the other object. Query for EmployeeJob, and then "load only"
the Employee columns.
2. Explicitly load columns. I'm not sure if this will work for
relationships:
session.query( TableClass.column_a, TableClass.column_b).all()
instead of returning an ORM object, you get a tuple.
3. Define a column as deferred in the mapper
[
http://docs.sqlalchemy.org/en/latest/orm/mapper_config.html#deferred-column-loading]
Looking at your example though, unless you have very high traffic -- you're
not going to have a significant performance gain with a query like that.
Your tables don't have many columns, and they're not very large. People
are usually concerned about load_only when you have very large fields
(BLOBS, TEXT, HSTORE) or complex joins and need to save memory.
You might just be better off letting the ORM load stuff you don't need --
you'll get much more code done that way.
--
You received this message because you are subscribed to the Google Groups
"sqlalchemy" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
To post to this group, send email to [email protected].
Visit this group at http://groups.google.com/group/sqlalchemy.
For more options, visit https://groups.google.com/d/optout.
