CODEWITHSUNDEEP
djangosqliteforeign-keys
ofey
ofey

Reputation: 3347

Cannot generate foreign key field in Django

'authorid' is a foreign key to the Django 'User' model. After running 'makemigrations' and 'migrate' I can not see this field in the sqlite shell. Here are my models,

class TopicModel(models.Model):
    topic = models.CharField(max_length = 100)
    topicAuthor = models.CharField(max_length = 100)
    authorid = models.ForeignKey(User, related_name = 'id_of_author')
    views = models.PositiveIntegerField(default = 0)

    def __str__(self):            
            return self.topic

class PostModel(models.Model):
    post = HTMLField(blank = True, max_length = 1000)
    pub_date = models.DateTimeField('date published')
    author = models.CharField(max_length = 30)
    topicid = models.ForeignKey(TopicModel, related_name = 'posts')

    def __str__(self):           
            return self.post

As you can see postmodel also has a foreign key to the topicmodel and there is no problem with this foreign key. After migration the migrate file 0001_initial.py looks like this,

from __future__ import unicode_literals

from django.conf import settings
from django.db import migrations, models
import django.db.models.deletion
import tinymce.models


class Migration(migrations.Migration):

    initial = True

    dependencies = [
        migrations.swappable_dependency(settings.AUTH_USER_MODEL),
    ]

    operations = [
        migrations.CreateModel(
            name='PostModel',
            fields=[
                ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
                ('post', tinymce.models.HTMLField(blank=True, max_length=1000)),
                ('pub_date', models.DateTimeField(verbose_name='date published')),
                ('author', models.CharField(max_length=30)),
            ],
        ),
        migrations.CreateModel(
            name='TopicModel',
            fields=[
                ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
                ('topic', models.CharField(max_length=100)),
                ('topicAuthor', models.CharField(max_length=100)),
                ('views', models.PositiveIntegerField(default=0)),
                ('authorid', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='id_of_author', to=settings.AUTH_USER_MODEL)),
            ],
        ),
        migrations.AddField(
            model_name='postmodel',
            name='topicid',
            field=models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='posts', to='crudapp.TopicModel'),
        ),
    ]

In the sqlite shell the postmodel shows the field with the foreign key, which is topicid_id

sqlite> PRAGMA table_info(crudapp_postmodel);
0|id|integer|1||1
1|pub_date|datetime|1||0
2|author|varchar(30)|1||0
3|topicid_id|integer|1||0
4|post|text|1||0

But when I do the same with the topicmodel, the field with the foreign key doesn't exist, so there is no authorid field.

sqlite> PRAGMA table_info(crudapp_topicmodel);
0|id|integer|1||1
1|topic|varchar(100)|1||0
2|topicAuthor|varchar(100)|1||0
3|views|integer unsigned|1||0

Solution: As suggested by Alasdair I deleted the sqlitedb file and changed the fields from from topicid and authorid to topic and author.

Upvotes: 2

Views: 1568

Answers (1)

Alasdair
Alasdair

Reputation: 309109

Your current migration should create the foreign keys. My guess is that you updated the migration file after you had already created the crudapp_topicmodel table in the database.

If you don't have any important data yet, the easiest fix is to delete your sqlite file and rerun ./manage.py migrate.

Upvotes: 1

Related Questions