contrib.admin: select_related overwritten by django.contrib.admin.views.ChangeList.get_query_set

[erny]

In trunk and 1.0.x, although I define (see #8213, see also #9554, and #9849 marked as dupe)

class MyModelAdmin(ModelAdmin):
    def queryset(self):
        return super(MyModelAdmin, self).queryset().select_related('foo__bar__baz', depth=2)

it is completely overwritten by the following code in `django/contrib/admin/views/main.py near line 83:

        # Use select_related() if one of the list_display options is a field
        # with a relationship.
        if self.list_select_related:
            qs = qs.select_related()
        else:
            for field_name in self.list_display:
                try:
                    f = self.lookup_opts.get_field(field_name)
                except models.FieldDoesNotExist:
                    pass
                else:
                    if isinstance(f.rel, models.ManyToOneRel):
                        qs = qs.select_related()
                        break

        # Set ordering.
        if self.order_field:
            qs = qs.order_by('%s%s' % ((self.order_type == 'desc' and '-' or ''), self.order_field))

This should definitively be an option of ModelAdmin.

[erny]

The patch has a small error: s/selected/select

[erny]

just found another error, will attach new patch.

[erny]

new version of patch

[mrts]

#10742 was a duplicate and proposed to use three-valued logic, leaving existing behaviour as-is and adding None:

• True -- always call select_related(),
• False (the default) -- call select_related() if any of the fields in list_display is a foreign key,
• None (added) -- leave the queryset alone.

It has a working patch.

[mrts]

Add None and explicitly select the related fields when False

[mmarshall]

Distinguishing between False and None feels hacky to me.

Would it work to have ChangeList.get_query_set only call select_related if qs.query.select_related is False?

[mmarshall]

Don't change select_related if it's already truthy. (with tests)

[Jacob]

(In [10782]) Fixed #10348: ChangeList no longer overwrites a select_related provided by ModelAdmin.queryset().

[Jacob]

(In [10783]) [1.0.X] Fixed #10348: ChangeList no longer overwrites a select_related provided by ModelAdmin.queryset(). Backport of [10782] from trunk.

[Jacob]

Milestone 1.1 deleted

[Mariusz Felisiak <felisiak.mariusz@…>]

In 3ea957b5:

[3.0.x] Refs #10348 -- Doc'd that ModelAdmin ignores list_select_related when QuerySet.select_related() was already called.

Backport of e3f647f4d5fc414f8cb7ab58df5e61a19908c63f from master

[Mariusz Felisiak <felisiak.mariusz@…>]

In e3f647f:

Refs #10348 -- Doc'd that ModelAdmin ignores list_select_related when QuerySet.select_related() was already called.

[Mariusz Felisiak <felisiak.mariusz@…>]

In 98573cfe:

[2.2.x] Refs #10348 -- Doc'd that ModelAdmin ignores list_select_related when QuerySet.select_related() was already called.

Backport of e3f647f4d5fc414f8cb7ab58df5e61a19908c63f from master