python manage.py migrate 没有创建表

Question

I use postgresql and my python version is 3.7 I have tried all the commands

python manage.py makemigrations

This creates a file in migrations named 0001_initial.py

# Generated by Django 2.2.10 on 2020-02-17 12:01

from django.db import migrations, models

class Migration(migrations.Migration):

initial = True

dependencies = [
]

operations = [
    migrations.CreateModel(
        name='Support',
        fields=[
            ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
            ('name', models.CharField(max_length=40)),
            ('email', models.EmailField(max_length=254)),
            ('message', models.TextField()),
        ],
    ),
]

now when I pass the command to migrate,

python manage.py migrate

It shows that 'No migrations to apply'

    (myvenv) C:\nid\project>python manage.py migrate
Operations to perform:
  Apply all migrations: admin, auth, contenttypes, scholarship, sessions
Running migrations:
  No migrations to apply.

This is my models.py class:

    from django.db import models
from django.utils import timezone

# Create your models here.


class Support(models.Model):
    name = models.CharField(max_length=40)
    email = models.EmailField()
    message = models.TextField()

    def __str__(self):
        return self.name

I know that this question has been asked before. I checked them all but no answer is able to solve this problem. Please help

Answer 1

In general, this means that the table already exists in your DB. I suggest that you try to delete your table and then recreate it with py manage.py migrate .

Reply if you have further problems

Answer 2

有点旧的帖子，但我刚刚遇到了同样的问题，只需运行即可解决：
python manage.py makemigrations
python manage.py migrate --run-syncdb

Answer 3

So what happens behind the scenes is:

When you run the command: python manage.py makemigrations

A migration file gets created based on your model or model changes.

When you run: python manage.py migrate

Django uses the newly created file inside the migrations folders and performs the actions accordingly AND a corresponding entry is created in the table django_migrations (sort of a log).

Now even if you DELETE the table from DB and the migration file from the folder, the migrate command will not work because the new file created will always be named '0001_initial.py' as you have deleted the previous migration file.

If you explore the table 'django_migrations' you will find a entry with your app_name and migrations file name. Example:

myApp 0001_initial

Django will always assume that the migration has already run before and will not run it again.

How to fix?

Option 1: python manage.py migrate --run-syncdb

Option 2: Delete the particular entry that's conflicting with your last migration filename / or the one you want to run / or all of them related to that app