Question

'authorid'是Django'User'模型的外键。运行'makemigrations'和'migrate'之后，我无法在sqlite shell中看到这个字段。这是我的模特，

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

正如您所看到的，postmodel还有一个主题模型的外键，这个外键没有问题。迁移后，迁移文件0001_initial.py如下所示，

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'),
        ),
    ]

在sqlite shell中，postmodel显示带有外键的字段，即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

但是当我对topicmodel做同样的事情时，带有外键的字段不存在，所以没有authorid字段。

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

解决方案：根据Alasdair的建议，我删除了sqlitedb文件，并将字段从topicid和authorid更改为topic和author。

Answer 1

您当前的迁移应该创建外键。我的猜测是，在您已在数据库中创建crudapp_topicmodel表后，您已更新了迁移文件。

如果您还没有任何重要数据，最简单的解决方法是删除您的sqlite文件并重新运行./manage.py migrate。

无法在Django中生成外键字段

1 个答案: