Dry ORM

Code

Result

no cache

from django.db import models
from django.db.models import Prefetch, Q

class Network(models.Model):
    code = models.CharField(max_length=8)

class Station(models.Model):
    code = models.CharField(max_length=8)
    network = models.ForeignKey(Network, on_delete=models.PROTECT)

def __str__(self):
        return self.code

def run():
    net1 = Network.objects.create(code='net1')
    net2 = Network.objects.create(code='net2')
    stat1 = Station.objects.create(
        network=net1, code='stat1',
    )
    stat25 = Station.objects.create(
        network=net2, code='stat25',
    )
    networks = list(Network.objects.filter(code='net1').prefetch_related(
        Prefetch(
            'station_set',
            queryset=Station.objects.filter(
                Q(network__code='net1', code='stat1')
                | Q(network__code='net2', code='stat25')
            )
        )
    ).union(
        Network.objects.filter(code='net2')
    ).order_by('pk'))
    print(networks[0].station_set.all())
    print(networks[1].station_set.all())

Output

No output.

Queries

TCLTCL DDLDDL SELECTS INSERTI UPDATEU DELETED REVERSER

QueriesQ (0)

No queries.