id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
21144	Not possible to update foreign key by id for a queryset	dakinsloss@…	vaskalas	"Attempting to minimize queries when updating list of ModelA instances that have foreign keys to ModelB, and I know the ids of the new ModelB instances I want to use for the instances of ModelA (that I only have the id for, not the instance).

Trying: 
ModelA.objects.filter(pk=id_of_a_instance).update(b_id=id_of_b_instance) which yields 'FieldNameDoesNotExist' because 'get_field_by_name' only has 'b' as a field name for ModelA, not b_id (which is strange given that is what is actually stored).

Then I try:
ModelA.objects.filter(pk=id_of_a_instance).update(b=id_of_b_instance), which says it needs an instance of ModelB, not a number.

Which means I will be stuck with an extra query:
model_b_list = list(ModelB.objects.filter(id_in=[list of ids for a instances])
and then have to iterate through the ModelA instances and assign the actual ModelB instances"	Cleanup/optimization	closed	Database layer (models, ORM)	1.5	Normal	fixed	update, related model, performance		Accepted	0	0	0	0	0	0