How would you sort a django mptt tree?

问题:

Imagine that I have an mptt tree of objects and their population like:

Animal, 60

• aardvark, 30
• bobcat, 20
• chipmunk, 10

Vegetable, 6

• apple, 1
• beet, 2
• cauliflower, 3

Mineral 0

How would you sort the above by population on each sublevel? I want to get to:

Animal, 60

• aardvark, 30
• bobcat, 20
• chipmunk, 10

Vegetable, 6

• cauliflower, 3
• beet, 2
• apple, 1

Mineral 0

I am building off of mptt in django.

回答1:

I've just solved a similar issue. You can use an order_by, but not simply by the field you want to sort by:

MyModel.tree.all().order_by('tree_id', 'level', 'your_sort_field')

回答2:

Try to add it in the models.py Meta Class.

Or on a subsidiary QuerySet

回答3:

Should an order_by simply work?

YourModel.tree.filter(your=stuff).order_by('order')