Reputation: 53
From the last seven days I am trying to build a blog using django and I figured out the model for my blog as follows
from django.db import models
class Post(models.Model):
title = models.CharField(max_length=200)
body = models.TextField()
created_at = models.DateTimeField('created date', auto_now_add=True, auto_now=False)
updated_at = models.DateTimeField('updated date', auto_now_add=False, auto_now=True)
def __str__(self):
return self.title
class Author(models.Model):
name = models.CharField(max_length=150)
email = models.EmailField(blank=True)
bio = models.TextField()
#This line define many author can have a post
#but I want manypost can only have single author.
#in my view to accomplish this i need to define author in Post class
#on defining author=ForeignKey(Author) in post, It throws an error Author is not defined
post = models.ForeignKey(Post)
def __str__(self):
return self.author
class Category(models.Model):
cat_name = models.CharField(max_length=200)
post = models.ManyToManyField(Post)
def __str__(self):
return self.cat_name
The thing that I am so much confused is the relation between the Post, Categories, Author and Tag.
Relation What I wanted to set is
But the models that I am created above is not working as I expected(I am so confused).
when I put the author field in Post Class, so that i would be a relation like, an author can have many posts, but I got the error Author is not defined.(as I know the interpreter run code from top to bottom). How do I accomplish
Upvotes: 0
Views: 158
Reputation: 21734
- author can have many posts, A post can have only single author
Post
model should have a ForeignKey
pointing to Author
.
class Post(...):
author = models.ForeignKey('Author')
- categories can have many posts, A post can have many categories
Post
model should have a ManyToManyField
pointing to Category
.
class Post(...):
category = models.ManyToManyField('Category')
- a tag can have many posts a post can have many tags
Same as number 2.
Upvotes: 0
Reputation: 7364
Try model structure syntax:
class Author(models.Model):
name = models.CharField(max_length=150)
email = models.EmailField(blank=True)
bio = models.TextField()
def __str__(self):
return self.author
class Post(models.Model):
author = models.ForeignKey(Author)
title = models.CharField(max_length=200)
body = models.TextField()
created_at = models.DateTimeField('created date', auto_now_add=True, auto_now=False)
updated_at = models.DateTimeField('updated date', auto_now_add=False, auto_now=True)
def __str__(self):
return self.title
class Category(models.Model):
cat_name = models.CharField(max_length=200)
post = models.ManyToManyField(Post)
def __str__(self):
return self.cat_name
class Tag(models.Model):
tag_name = models.CharField(max_length=200)
post = models.ManyToManyField(Post)
def __str__(self):
return self.tag_name
This will solve your three requirements:
1.) Author can have many posts because I set the Post Model into one-to-many field
2.) Categories can have many posts vice versa (This is already set according to your code)
3.) Tag can have many posts vice versa (Very similar to your already made Category Model where I made the field many-to-many between the two)
The reason why you got an error is because you made your author to post relation to many-to-one (many authors in one post) according to your model structure
Now to test it simply migrate all these changes and quickly test it in your admin page
Upvotes: 0
Reputation: 3502
You have two options:
author= models.ForeignKey("Author")
In this way, Django will wait until all models load then resolve the dependencies.
Upvotes: 1