When prefetching a set of child objects related to a set of parent
objects, we usually want to populate the relationship back from the
child to the parent to avoid a query when accessing that relationship
attribute. However, there's an edge case where the child queryset
itself specifies a prefetch back to the parent. In that case, we want
to use the prefetched relationship rather than populating the reverse
relationship from the parent.
This brings the behaviour in line with Field subclasses which append to
the validators within __init__(), like BinaryField, and prevents the
creation of a validator which incorrectly throws a TypeError, if it
were used.
Having it happen at the lookup creation time ensures entry points
called before the compilation phase (e.g. get_group_by_cols) don't have
to duplicate the logic in charge of altering Query instances used as
rhs.
It also has the nice effect of reducing the amount of time the
alteration logic to once as opposed to multiple times if the queryset
is compiled more than once.
PathInfo values are ostensibly static over the lifetime of the object
for which they're requested, so the data can be memoized, quickly
amortising the cost over the process' duration.
Since ManyToManyFields defined with `symmetrical=True` do not add a
related field to the target model, including a `related_name` argument
will never do what the coder likely expects. This makes including
a related_name with a symmetrical model raise a system check warning.
ticket-32983
This prefers non-kwargs construction of dynamically generated Q()
objects to create a single Q() object instead of many and then
combining them, where possible.
get_col() used "self" as "output_field" when it was not given, and
unnecessarily compared "self" to "self".
Co-authored-by: Chris Jerdonek <chris.jerdonek@gmail.com>
Co-authored-by: Mariusz Felisiak <felisiak.mariusz@gmail.com>
- Validate filename returned by FileField.upload_to() not a filename
passed to the FileField.generate_filename() (upload_to() may
completely ignored passed filename).
- Allow relative paths (without dot segments) in the generated filename.
Thanks to Jakub Kleň for the report and review.
Thanks to all folks for checking this patch on existing projects.
Thanks Florian Apolloner and Markus Holtermann for the discussion and
implementation idea.
Regression in 0b79eb3691.
After a93425a37f FileDescriptor is a
subclass of DeferredAttribute and uses FileField.attname to access the
field data, so that custom subclasses can not only save data to files,
but also represent the same data with a different data type by
attaching FileFiled.name to a particular descriptor.
Follow up to a93425a37f.
Jamie Matthews
Keryn Knight
David Wobrock
Adam Johnson
Simon Charette
Bernd Wechner
Chinmoy Chakraborty
Mariusz Felisiak
Hasan Ramezani
Nick Touran
Chris Jerdonek
Tom Wojcik
Nick Pope
Daniyal
Ian Foote
Carlton Gibson
Florian Apolloner
Daniel Hahler
manav014
sage
Hannes Ljungberg
Sultan
Bob Renwick
Tom Carrick
Ryan Hiebert
Brian Helba