migrating from sqlite to mysql breaks the site

[Pedram Badakhchani]

Hi All,

I am currently going through Django 2 by Example Book  by Antonio Melé.

Unfortunately I have a problem with the source code provided on the associated git hub pages:

https://github.com/PacktPublishing/Django-2-by-Example

specifically in chapter 1 :

https://github.com/PacktPublishing/Django-2-by-Example/tree/master/Chapter01/mysite

After downloading the source files, and setting up the chapter 1 example locally, using the default sqlite database  everything works as expected.

However, changing the database to mysql the site breaks. This is the scenario:

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.mysql',
        'NAME': 'pedbad',
        'USER': 'root',
        'PASSWORD': 'root',
        'HOST': 'localhost',
        'PORT': '3306',
    }
}

Changing the settings.py file to use mysql works fine, and the database is created, and the tables are all populated correctly. using createsuperuser also works and I am able to access the admin backend and create a post...

navigating to :  http://127.0.0.1:8000/blog/ shows the post and the post title link is set to: http://127.0.0.1:8000/blog/2019/1/31/test-post/ however, although this works fine with sqllite, on mysql the link take me to a 404 page: Page not found (404) Request Method: GET Request URL: http://127.0.0.1:8000/blog/2019/1/31/test-post/ Raised by: blog.views.post_detail No Post matches the given query. even though the blog post exists in the mysql table: table blog_post id - 1 title - Test Post slug - test-post body - content for test post publish - 2019-01-31 10:56:40.000000 created - 2019-01-31 10:56:59.674959 updated - 2019-01-31 10:56:59.674976 status - published author_id -  1 I would appreciate any advice on why this is happening when the database is switched to MySQl

I suspect the problem is in the blog model:

https://github.com/PacktPublishing/Django-2-by-Example/blob/master/Chapter01/mysite/blog/models.py

from django.db import models
from django.utils import timezone
 from django.contrib.auth.models import User
 from django.urls import reverse
 
 
 class PublishedManager(models.Manager):
 def get_queryset(self):
 return super(PublishedManager, self).get_queryset().filter(status='published')
 
 
 class Post(models.Model):
 STATUS_CHOICES = (
 ('draft', 'Draft'),
 ('published', 'Published'),
 )
 title = models.CharField(max_length=250)
 slug = models.SlugField(max_length=250,
 unique_for_date='publish')
 author = models.ForeignKey(User,
 on_delete=models.CASCADE,
 related_name='blog_posts')
 body = models.TextField()
 publish = models.DateTimeField(default=timezone.now)
 created = models.DateTimeField(auto_now_add=True)
 updated = models.DateTimeField(auto_now=True)
 status = models.CharField(max_length=10,
 choices=STATUS_CHOICES,
 default='draft')
 
 objects = models.Manager() # The default manager.
 published = PublishedManager() # Our custom manager.
 
 class Meta:
 ordering = ('-publish',)
 
 def __str__(self):
 return self.title
 
 def get_absolute_url(self):
 return reverse('blog:post_detail',
 args=[self.publish.year,
 self.publish.month,
 self.publish.day,
 self.slug])

thank you Pedram

[Pedram Badakhchani]

specifically in the get_absolute_url method.

I don't understand why this works fine with sqlite but breaks in mysql.

thanks for any help. 

[Pedram Badakhchani]

bump

[Anh Nguyen]

Could you insert a post on admin panel ?

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[Pedram Badakhchani]

Hi Anh,

yes, everything works fine, the only problem is once I switched from sqlite to mysql, 

I am able to access the admin backend and create a post...

I am able to view the list of posts created, however when I click a given post, with SQLite I can navigate to

a page showing the post details as expected.

However, switching to mysql breaks the redirecting to post details. I get No Post matches the given query.

I am not sure why this happens. I thought the Django ORM means that the code should work regardless of the

database used. So I am confused why this happens.

best

Pedram

[Ayser shuhaib]

In your settings, you put the port is 3306 but in the url it’s 8000.

I think the problem is there.

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[Anh Nguyen]

I see 2 ways to handle.

1: would you want to try postgresql ?, if this get the same trouble. We got the big problems.

2: try to create a blank project start from django-admin ... it’s not greater then 20mins. 

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