Django·Django from project to API

Models and migrations

Model your data, create migrations and keep schema changes reviewable.

Intermediate 15 min read Lesson 4 of 300 Challenge included

What you will be able to do

Define fields and relationships on the model.
Run makemigrations then migrate.
Add __str__ for readable admin labels.
Never edit a migration that has already run in production.

In plain English

A model is a Python class that maps to a database table. Migrations record schema changes so every environment can reach the same state. Make small migrations and read them before applying.

models.pyPython

from django.db import models

class Course(models.Model):
    slug = models.SlugField(unique=True)
    title = models.CharField(max_length=120)
    created_at = models.DateTimeField(auto_now_add=True)

    def __str__(self) -> str:
        return self.title

class Lesson(models.Model):
    course = models.ForeignKey(Course, related_name='lessons', on_delete=models.CASCADE)
    title = models.CharField(max_length=160)
    minutes = models.PositiveSmallIntegerField(default=10)

Your turn

Add a published flag

Easy

Add a boolean published field that defaults to False.

PYTHON · starter

published =

Check your understanding before moving on.

Knowledge checkQuestion 1

Which command creates a migration file from model changes?

Select an answer to continue

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Next: The Django admin

Lesson 4 of 300 · 0% of course