django:column books_book.publication_date does not exist
<p>I'm reading chapter 6 of django book:
<a href="http://www.djangobook.com/en/2.0/chapter06.html" rel="nofollow">http://www.djangobook.com/en/2.0/chapter06.html</a>
And I've done whatever chapter 5 and 6 of this book told me and I checked my work and searched the error many times but I'm still having problem when I go to <a href="http://127.0.0.1:8000/admin/books/book/" rel="nofollow">http://127.0.0.1:8000/admin/books/book/</a> to add some book and save it, I get this error:</p>

<blockquote>
  <p>ProgrammingError at /admin/books/book/</p>
  
  <p>column books_book.publication_date does not exist LINE 1:
  ...books_book"."title", "books_book"."publisher_id", "books_boo...</p>
</blockquote>

<p>And this is my models on models.py:</p>

<pre><code>from django.db import models

class Publisher(models.Model):
    name = models.CharField(max_length=30)
    address = models.CharField(max_length=50)
    city = models.CharField(max_length=60)
    state_province = models.CharField(max_length=30)
    country = models.CharField(max_length=50)
    website = models.URLField()

    def __unicode__(self):
        return self.name

    class Meta:
        ordering = ['name']
class Author(models.Model):
    first_name = models.CharField(max_length=30)
    last_name = models.CharField(max_length=40)
    email = models.EmailField()

    def __unicode__(self):
        return u'%s %s' % (self.first_name, self.last_name)

class Book(models.Model):
    title = models.CharField(max_length=100)
    authors = models.ManyToManyField(Author)
    publisher = models.ForeignKey(Publisher)
    publication_date = models.DateField()

    def __unicode__(self):
        return self.title
</code></pre>

<p>And this is on setting.py:</p>

<pre><code>INSTALLED_APPS = [
    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.messages',
    'django.contrib.sessions',
    'django.contrib.staticfiles',
    'books',
]
MIDDLEWARE_CLASSES = [
    'django.middleware.security.SecurityMiddleware',
    'django.contrib.sessions.middleware.SessionMiddleware',
    'django.middleware.common.CommonMiddleware',
    'django.middleware.csrf.CsrfViewMiddleware',
    'django.contrib.auth.middleware.AuthenticationMiddleware',
    'django.contrib.messages.middleware.MessageMiddleware',
    'django.middleware.clickjacking.XFrameOptionsMiddleware',
    'django.middleware.clickjacking.XFrameOptionsMiddleware',
    'django.middleware.csrf.CsrfViewMiddleware',
]
</code></pre>

<p>And this is on admin.py:</p>

<pre><code>from django.contrib import admin

# Register your models here.
from django.contrib import admin
from books.models import Publisher, Author, Book

admin.site.register(Publisher)
admin.site.register(Author)
admin.site.register(Book)
</code></pre>

<p>Thanks in advance...</p>

<pre><code>Please correct your code like that:    

from django.contrib import admin

# Register your models here.
from django.contrib import admin
from myproject.books.models import Publisher, Author, Book

admin.site.register(Publisher)
admin.site.register(Author)
admin.site.register(Book)
</code></pre>

python django