Django不加载灯具

Question

When I execute python loaddata lecteurs I have no error and this normal output : Installed 2 object(s) from 2 fixture(s) . The problem is that wehn I enter in Django's shell and try to Lecteurs.objects.all() this return me an empty array.

This is how Lecteur (model) looks like :

class Lecteur(User):
    bibliotheque = models.ManyToManyField('bibliotheque.Livre')
    localisation = models.ForeignKey(Localisation)

And the yaml file called lecteurs.yaml :

- model: lecteurs.lecteur
  pk: 1
  fields:
    username: Leila
    bibliotheque: [1, 2]
    localisation: 1
- model: lecteurs.lecteur
  pk: 2
  fields:
    username: Saumon
    bibliotheque: [2, 3]
    localisation: 1
- model: lecteurs.lecteur
  pk: 3
  fields:
    username: Giraffon
    bibliotheque: [1, 4]
    localisation: 1
- model: lecteurs.lecteur
  pk: 4
  fields:
    username: Fany
    bibliotheque: [2, 3]
    localisation: 2

The others fixtures load with no problem. Hope you can help and I was enough explicit.

Answer 1

TL;DR

Your yaml might be wrongly created or is missing other User details.

Explanation

Okay, So I just did a sample executing fixture and works for me.

So what I initially did is create a serialize of yaml via code, meaning:

Follow along:

1. Created a sample model as follows:

from django.db import models
from django.contrib.auth.models import User

class Lecteur(User):
    bibliotheque = models.CharField(max_length=100)
    localisation = models.IntegerField()

2. In Django Shell I did the following:

python manage.py shell
from tester.models import Lecteur  #tester is my app
Lecteur.objects.create(username="User1", bibliotheque="Hey", localisation=12).save()
Lecteur.objects.create(username="User2", bibliotheque="Hey", localisation=12).save()
Lecteur.objects.create(username="User3", bibliotheque="Hey", localisation=12).save()

3. Then created a yaml dump via serializer and added to a file try.yaml

from django.core import serializers
data = serializers.serialize("yaml", SomeModel.objects.all())
with open('try.yaml', 'w') as f:
    f.write(data)

Then comes the vital part, how does my yaml look?

Like this:

- fields:
    bibliotheque: Hey
    groups: []
    localisation: 12
    user_permissions: []
  model: tester.lecteur
  pk: 1
- fields:
    bibliotheque: Hey
    groups: []
    localisation: 12
    user_permissions: []
  model: tester.lecteur
  pk: 2
- fields:
    bibliotheque: Hey
    groups: []
    localisation: 12
    user_permissions: []
  model: tester.lecteur
  pk: 3

Here comes a small confusion, even I got Installed 3 object(s) from 3 fixture(s) and Lecteur.objects.all() gave nothing.

Now comes the important stuff:

I noticed, that since there is a User model inheritance, the yaml was incomplete, since django cannot find which user data to fill when the data is obtained.

So, I did something like this to get the complete data from the database :

python manage.py dumpdata --format "yaml" > try.yaml

When I recreated the database by loading the yaml as:

python manage.py loaddata try.yaml

I get the data back in the database. This is because the User table data is present in the yaml , so django now can populate the database correctly.

Here is my same try.yaml file:

- fields: {app_label: contenttypes, model: contenttype, name: content type}
  model: contenttypes.contenttype
  pk: 4
- fields: {app_label: auth, model: group, name: group}
  model: contenttypes.contenttype
  pk: 2
- fields: {app_label: tester, model: lecteur, name: lecteur}
  model: contenttypes.contenttype
  pk: 7
- fields: {app_label: auth, model: permission, name: permission}
  model: contenttypes.contenttype
  pk: 1
- fields: {app_label: sessions, model: session, name: session}
  model: contenttypes.contenttype
  pk: 5
- fields: {app_label: sites, model: site, name: site}
  model: contenttypes.contenttype
  pk: 6
- fields: {app_label: auth, model: user, name: user}
  model: contenttypes.contenttype
  pk: 3
- fields: {domain: example.com, name: example.com}
  model: sites.site
  pk: 1
- fields: {codename: add_group, content_type: 2, name: Can add group}
  model: auth.permission
  pk: 4
- fields: {codename: change_group, content_type: 2, name: Can change group}
  model: auth.permission
  pk: 5
- fields: {codename: delete_group, content_type: 2, name: Can delete group}
  model: auth.permission
  pk: 6
- fields: {codename: add_permission, content_type: 1, name: Can add permission}
  model: auth.permission
  pk: 1
- fields: {codename: change_permission, content_type: 1, name: Can change permission}
  model: auth.permission
  pk: 2
- fields: {codename: delete_permission, content_type: 1, name: Can delete permission}
  model: auth.permission
  pk: 3
- fields: {codename: add_user, content_type: 3, name: Can add user}
  model: auth.permission
  pk: 7
- fields: {codename: change_user, content_type: 3, name: Can change user}
  model: auth.permission
  pk: 8
- fields: {codename: delete_user, content_type: 3, name: Can delete user}
  model: auth.permission
  pk: 9
- fields: {codename: add_contenttype, content_type: 4, name: Can add content type}
  model: auth.permission
  pk: 10
- fields: {codename: change_contenttype, content_type: 4, name: Can change content
      type}
  model: auth.permission
  pk: 11
- fields: {codename: delete_contenttype, content_type: 4, name: Can delete content
      type}
  model: auth.permission
  pk: 12
- fields: {codename: add_session, content_type: 5, name: Can add session}
  model: auth.permission
  pk: 13
- fields: {codename: change_session, content_type: 5, name: Can change session}
  model: auth.permission
  pk: 14
- fields: {codename: delete_session, content_type: 5, name: Can delete session}
  model: auth.permission
  pk: 15
- fields: {codename: add_site, content_type: 6, name: Can add site}
  model: auth.permission
  pk: 16
- fields: {codename: change_site, content_type: 6, name: Can change site}
  model: auth.permission
  pk: 17
- fields: {codename: delete_site, content_type: 6, name: Can delete site}
  model: auth.permission
  pk: 18
- fields: {codename: add_lecteur, content_type: 7, name: Can add lecteur}
  model: auth.permission
  pk: 19
- fields: {codename: change_lecteur, content_type: 7, name: Can change lecteur}
  model: auth.permission
  pk: 20
- fields: {codename: delete_lecteur, content_type: 7, name: Can delete lecteur}
  model: auth.permission
  pk: 21
- fields:
    date_joined: 2014-10-25 07:41:32.935000+00:00
    email: ''
    first_name: ''
    groups: []
    is_active: true
    is_staff: false
    is_superuser: false
    last_login: 2014-10-25 07:41:32.935000+00:00
    last_name: ''
    password: ''
    user_permissions: []
    username: User1
  model: auth.user
  pk: 1
- fields:
    date_joined: 2014-10-25 07:41:41.199000+00:00
    email: ''
    first_name: ''
    groups: []
    is_active: true
    is_staff: false
    is_superuser: false
    last_login: 2014-10-25 07:41:41.199000+00:00
    last_name: ''
    password: ''
    user_permissions: []
    username: User2
  model: auth.user
  pk: 2
- fields:
    date_joined: 2014-10-25 07:41:48.713000+00:00
    email: ''
    first_name: ''
    groups: []
    is_active: true
    is_staff: false
    is_superuser: false
    last_login: 2014-10-25 07:41:48.713000+00:00
    last_name: ''
    password: ''
    user_permissions: []
    username: User3
  model: auth.user
  pk: 3
- fields:
    bibliotheque: Hey
    groups: []
    localisation: 12
    user_permissions: []
  model: tester.lecteur
  pk: 1
- fields:
    bibliotheque: Hey
    groups: []
    localisation: 12
    user_permissions: []
  model: tester.lecteur
  pk: 2
- fields:
    bibliotheque: Hey
    groups: []
    localisation: 12
    user_permissions: []
  model: tester.lecteur
  pk: 3

Ideally django should have complained but then might be a bug. Not sure about the implementation.

Notice specifically the following yaml code:

- fields:
    date_joined: 2014-10-25 07:41:32.935000+00:00
    email: ''
    first_name: ''
    groups: []
    is_active: true
    is_staff: false
    is_superuser: false
    last_login: 2014-10-25 07:41:32.935000+00:00
    last_name: ''
    password: ''
    user_permissions: []
    username: User1
  model: auth.user
  pk: 1

That code is a piece that identifies the user you would have to add before the custom class is created.