Django 3.1: OperationalError - No Such Column/Table

Question

I've been solving this problem for the entire day. My code in my models.py is the following:

from django.db import models
from django.contrib.auth.models import User
from users.models import TeacherProfile, StudentProfile

class Course(models.Model):
    name = models.CharField(max_length=100)
    desc = models.TextField()
    short_code = models.CharField(max_length=5)
    teacher = models.ForeignKey(TeacherProfile, null=True, on_delete=models.SET_NULL)
    students = models.ManyToManyField(StudentProfile)

    def __str__(self):
        return self.name

class Partition(models.Model):
    name = models.CharField(max_length=20)
    chunk = models.FloatField()
    result = models.FloatField(blank=True)
    course = models.ForeignKey(Course, on_delete=models.CASCADE)
    
    def __str__(self):
        return self.name
    
class Activity(models.Model):
    title = models.CharField(max_length=100)
    content = models.TextField()
    file = models.FileField(blank=True)
    course = models.ForeignKey(Course, on_delete=models.CASCADE)
    parent = models.ForeignKey(Partition, on_delete=models.CASCADE)

    def __str__(self):
        return self.title
    
class Grade(models.Model):
    grade = models.FloatField()
    remarks = models.CharField(max_length=200, blank=True)
    activity = models.ForeignKey(Activity, on_delete=models.CASCADE)
    student = models.ForeignKey(StudentProfile, on_delete=models.CASCADE)

I've ran the following commands:

python manage.py makemigrations
python manage.py migrate

I even written the following command as per my research to other StackOverFlow questions related to this:

python manage.py migrate --run-syncdb

Only the Course table worked. The Activity and the Grade table received OperationalError - No Such Column and the Partition Table got an OperationalError - No Such Table.

Activity

OperationalError at /admin/course/activity/
no such column: course_activity.parent_id
Request Method: GET
Request URL:    http://127.0.0.1:8000/admin/course/activity/
Django Version: 3.1
Exception Type: OperationalError
Exception Value:    
no such column: course_activity.parent_id
Exception Location: C:\Users\hp\AppData\Local\Programs\Python\Python38-32\lib\site-packages\django\db\backends\sqlite3\base.py, line 413, in execute
Python Executable:  C:\Users\hp\AppData\Local\Programs\Python\Python38-32\python.exe
Python Version: 3.8.5
Python Path:    
['C:\\Users\\hp\\Desktop\\TechKnow\\YowBro',
 'C:\\Users\\hp\\AppData\\Local\\Programs\\Python\\Python38-32\\python38.zip',
 'C:\\Users\\hp\\AppData\\Local\\Programs\\Python\\Python38-32\\DLLs',
 'C:\\Users\\hp\\AppData\\Local\\Programs\\Python\\Python38-32\\lib',
 'C:\\Users\\hp\\AppData\\Local\\Programs\\Python\\Python38-32',
 'C:\\Users\\hp\\AppData\\Local\\Programs\\Python\\Python38-32\\lib\\site-packages']
Server time:    Fri, 21 Aug 2020 09:47:26 +0000

Grade

OperationalError at /admin/course/grade/
no such column: course_grade.remarks
Request Method: GET
Request URL:    http://127.0.0.1:8000/admin/course/grade/
Django Version: 3.1
Exception Type: OperationalError
Exception Value:    
no such column: course_grade.remarks
Exception Location: C:\Users\hp\AppData\Local\Programs\Python\Python38-32\lib\site-packages\django\db\backends\sqlite3\base.py, line 413, in execute
Python Executable:  C:\Users\hp\AppData\Local\Programs\Python\Python38-32\python.exe
Python Version: 3.8.5
Python Path:    
['C:\\Users\\hp\\Desktop\\TechKnow\\YowBro',
 'C:\\Users\\hp\\AppData\\Local\\Programs\\Python\\Python38-32\\python38.zip',
 'C:\\Users\\hp\\AppData\\Local\\Programs\\Python\\Python38-32\\DLLs',
 'C:\\Users\\hp\\AppData\\Local\\Programs\\Python\\Python38-32\\lib',
 'C:\\Users\\hp\\AppData\\Local\\Programs\\Python\\Python38-32',
 'C:\\Users\\hp\\AppData\\Local\\Programs\\Python\\Python38-32\\lib\\site-packages']
Server time:    Fri, 21 Aug 2020 09:47:28 +0000

Partition

OperationalError at /admin/course/partition/
no such table: course_partition
Request Method: GET
Request URL:    http://127.0.0.1:8000/admin/course/partition/
Django Version: 3.1
Exception Type: OperationalError
Exception Value:    
no such table: course_partition
Exception Location: C:\Users\hp\AppData\Local\Programs\Python\Python38-32\lib\site-packages\django\db\backends\sqlite3\base.py, line 413, in execute
Python Executable:  C:\Users\hp\AppData\Local\Programs\Python\Python38-32\python.exe
Python Version: 3.8.5
Python Path:    
['C:\\Users\\hp\\Desktop\\TechKnow\\YowBro',
 'C:\\Users\\hp\\AppData\\Local\\Programs\\Python\\Python38-32\\python38.zip',
 'C:\\Users\\hp\\AppData\\Local\\Programs\\Python\\Python38-32\\DLLs',
 'C:\\Users\\hp\\AppData\\Local\\Programs\\Python\\Python38-32\\lib',
 'C:\\Users\\hp\\AppData\\Local\\Programs\\Python\\Python38-32',
 'C:\\Users\\hp\\AppData\\Local\\Programs\\Python\\Python38-32\\lib\\site-packages']
Server time:    Fri, 21 Aug 2020 09:47:29 +0000

What did I do wrong?

UPDATE: I've tried putting default values to the tables. Sadly, it didn't work. Help please.

UPDATE #2: I ran python manage.py sqlmigrate course 0001 . Contrary to the error it shows in the actual site, the returned SQL commands are shown below (I highlighted the SQL command for creating the table Partition for emphasis):

ASSUMPTION: Maybe the error is in the migration command. I manually deleted the tables from my DB Browser for SQLite. Then, I tried running the makemigrations and the migrations command. Though it migrates a SQL code, it doesn't create anything at all. How can we fix this?

I SOLVED THE PROBLEM! Check my answer below.

Answer 1

You can try to put related name in your models eg

class Activity(models.Model):
   title = models.CharField(max_length=100)
   content = models.TextField()
   file = models.FileField(blank=True)
   course = models.ForeignKey(Course,related_name='course_id' on_delete=models.CASCADE)
   parent = models.ForeignKey(Partition,related_name='parent_id' on_delete=models.CASCADE)

   def __str__(self):
      return self.title

Answer 2

I FIXED THE PROBLEM.

Thanks to kerasbaz, I checked my database configuration in my Django settings. I thought that I should comment the configuration out for the SQLite and insert the PostgreSQL.

So what I first did is to create a new database through my pgAdmin. Now, you need to have pgAdmin and psycopg2 installed ( pip install psycopg2 ). Next, I edited my database settings in my project's settings.

Here's a sample from the Django documentation:

 DATABASES = {
     'default': {
            'ENGINE': 'django.db.backends.postgresql',
            'NAME': 'mydatabase',
            'USER': 'mydatabaseuser',
            'PASSWORD': 'mypassword',
            'HOST': '127.0.0.1',
            'PORT': '5432',
       }
}

Finally, I ran makemigrations and migrate commands. Voila. I solved the problem I've been solving for five hours.