>>> from django_single.models import *
>>> SWSDocumentStep.objects.select_related('document_number').prefetch_related('swesstep_set', 'swesstep_set__swessteppicture_set')
DEBUG (0.004) SELECT "django_single_swsdocumentstep"."id", "django_single_swsdocumentstep"."document_number_id", "django_single_swsdocumentstep"."sws_sequence_number", "django_single_swsdocumentstep"."sws_work_element_description", "django_single_swsdocumentstep"."sws_step_type", "django_single_swsdocumentstep"."pub_date", "django_single_swsdocument"."id", "django_single_swsdocument"."name" FROM "django_single_swsdocumentstep" INNER JOIN "django_single_swsdocument" ON ("django_single_swsdocumentstep"."document_number_id" = "django_single_swsdocument"."id") WHERE "django_single_swsdocumentstep"."id" = 10 LIMIT 21; args=(10,)
DEBUG (0.001) SELECT "django_single_swesstep"."id", "django_single_swesstep"."sws_document_id", "django_single_swesstep"."swes_description", "django_single_swesstep"."swes_step_type", "django_single_swesstep"."pub_date" FROM "django_single_swesstep" WHERE "django_single_swesstep"."sws_document_id" IN (10); args=(10,)
DEBUG (0.002) SELECT "django_single_swessteppicture"."id", "django_single_swessteppicture"."swes_step_id", "django_single_swessteppicture"."pub_date" FROM "django_single_swessteppicture" WHERE "django_single_swessteppicture"."swes_step_id" IN (10); args=(10,)
<QuerySet [<SWSDocumentStep: SWSDocument object (10) None >]>
Извините, не могу не переименовать ваши модели, они примеры того, чего не следует делать:
1. Не используйте ForeignKey и добавьте _id в конец модели, например: sws_document_id> sws_document
2. В питоне мы не добавляем _ между нашими словами в классе, например: SWES_Step_Picture> SWESStepPicture
# to get this to work you will need to do the following steps
mkdir django_simple/migrations
touch django_simple/django_simple.py
# copy and paste the content of the file bellow in django_simple/django_simple.py
python django_simple/django_simple.py makemigrations
python django_simple/django_simple.py migrate
python django_simple/django_simple.py shell -c 'from django_simple.models import *; SWESStepPicture.objects.create(swes_step=SWESStep.objects.create(sws_document=SWSDocumentStep.objects.create(document_number=SWSDocument.objects.create(name="blah"))))'
#!/usr/bin/env python
# -*- coding:utf-8 -*-
# Stolen from: https://mlvin.xyz/django-single-file-project.html
import inspect
from types import ModuleType
import os
import sys
from django.conf import settings
BASE_DIR = os.path.dirname(os.path.abspath(__file__))
sys.path[0] = os.path.dirname(BASE_DIR)
# the current folder name will also be our app
APP_LABEL = os.path.basename(BASE_DIR)
settings.configure(
DEBUG=True,
ROOT_URLCONF=__name__,
MIDDLEWARE=[],
INSTALLED_APPS=[
APP_LABEL,
'django.contrib.contenttypes',
],
DATABASES={
'default': {
'ENGINE': 'django.db.backends.sqlite3',
'NAME': os.path.join(BASE_DIR, 'db.sqlite3'),
}
},
LOGGING={
'version': 1,
'disable_existing_loggers': False,
'formatters': {
'simple': {
'format': "%(levelname)s %(message)s",
},
},
'handlers': {
'console': {
'level': 'DEBUG',
'class': 'logging.StreamHandler',
'formatter': 'simple',
}
},
'loggers': {
'django.db.backends': {'handlers': ['console'], 'level': 'DEBUG', 'propagate': False},
'django.db.backends.schema': {'level': 'ERROR'}, # Causes sql logs to duplicate -- really annoying
}
}
)
import django
django.setup()
from django.db import models
# Create your models here.
class SWSDocument(models.Model):
name = models.CharField(max_length=30)
class Meta:
verbose_name = 'SWS Document'
verbose_name_plural = '001 SWS Document'
app_label = APP_LABEL
class SWSDocumentStep(models.Model):
STEP_TYPE_CHOICES = (
('People', 'People'),
('Quality', 'Quality'),
('Velocity', 'Velocity'),
('Cost', 'Cost'),
)
document_number = models.ForeignKey(SWSDocument, on_delete=models.CASCADE)
sws_sequence_number = models.PositiveIntegerField(editable=True, null=True)
sws_work_element_description = models.CharField(max_length=500)
sws_step_type = models.CharField(max_length=30, choices=STEP_TYPE_CHOICES, null=True, blank=True)
pub_date = models.DateTimeField(auto_now=True)
class Meta:
verbose_name = 'SWS Document Step'
verbose_name_plural = '005 SWS Document Steps'
app_label = APP_LABEL
def __str__(self):
return str(self.document_number) + " " + str(self.sws_sequence_number) + " " + str(self.sws_work_element_description)
class SWESStep(models.Model):
STEP_TYPE_CHOICES = (
('People', 'People'),
('Quality', 'Quality'),
('Velocity', 'Velocity'),
('Cost', 'Cost'),
)
sws_document = models.ForeignKey(SWSDocumentStep, on_delete=models.CASCADE, null=True)
swes_description = models.CharField(max_length=500)
swes_step_type = models.CharField(max_length=8, choices=STEP_TYPE_CHOICES, blank=True)
pub_date = models.DateTimeField(auto_now=True)
class Meta:
verbose_name = 'SWES Step'
verbose_name_plural = '012 SWES Document Steps'
app_label = APP_LABEL
def __str__(self):
return str(self.sws_document_id) + " " + str(self.swes_description)
class SWESStepPicture(models.Model):
swes_step = models.ForeignKey(SWESStep, on_delete=models.CASCADE)
# sws_step_photo = models.ImageField() # too lazy to install pillow
pub_date = models.DateTimeField(auto_now=True)
class Meta:
verbose_name = 'SWES Step Picture'
verbose_name_plural = '015 SWES Step Pictures'
app_label = APP_LABEL
# Can't use `dumpdata` without it -- this will set it for ALL apps, the app_config is shared
SWESStepPicture._meta.app_config.models_module = '__main__'
# Used so you can do 'from <name of file>.models import *'
models_module = ModuleType(APP_LABEL + '.models')
for variable_name, value in list(locals().items()):
# We are only interested in models
if inspect.isclass(value) and issubclass(value, models.Model):
setattr(models_module, variable_name, value)
sys.modules[models_module.__name__] = models_module
urlpatterns = []
if __name__ == "__main__":
from django.core.management import execute_from_command_line
execute_from_command_line(sys.argv)
else:
from django.core.wsgi import get_wsgi_application
get_wsgi_application()