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pythonpeewee

How to order child records when referenced from a parent object in PeeWee ORM

How do I specify an order for the records returned via a foreign key in Peewee?

I have the following (simplified) model;

class Order(peewee.Model):
    order_no = peewee.CharField()

class OrderLine(peewee.Model):
    order_item = peewee.CharField()
    quantity = peewee.IntegerField()
    price = peewee.DecimalField()

    order = peewee.ForeignKeyField(Order)

When I fetch an order using my_order = Order.get(1234) I would like to then iterate through the order lines in a specific order, sometimes in order_item order, sometimes in quantity order. Is there a way to do this? At the moment they seem to come back in order_item.id order from the database.

Solution

  • The back-ref of the foreign-key (Order.orderline_set) is just a wrapper around a select query, so you can order it how you wish:

    for item in order.orderline_set.order_by(OrderLine.quantity):
    ...