Field Types
Part of the Models and the Admin section of Coddy's Django journey. Lesson 2 of 23.
A book has more than a title: a year, a price, whether you read it. Each kind of data has its own field class, which sets the column type and the Python value you get back. A film site's Movie could hold:
class Movie(models.Model):
title = models.CharField(max_length=150)
minutes = models.IntegerField()
rating = models.DecimalField(max_digits=3, decimal_places=1)
has_subtitles = models.BooleanField()
released = models.DateField()IntegerField holds whole numbers. DecimalField holds exact decimals and gives back a Decimal: max_digits counts every digit and decimal_places the ones after the point, so 3 and 1 reach 99.9. Money is never a float, because floats are not exact: 0.1 + 0.2 is 0.30000000000000004.
BooleanField holds True or False. DateField holds a datetime.date, a day with no time.
Challenge
EasyAdd four fields to Book, each with the class that fits what it holds:
year: a whole number like1965price: money up to9999.99, exact to the centis_read: yes or nofinished: the day you finished it
Press Run, then type Book._meta.get_field("price") in the Shell tab to see the class you picked.
Try it yourself
from django.db import models
class Book(models.Model):
title = models.CharField(max_length=200)
author = models.CharField(max_length=100)
Test yourselfThis lesson includes a short quiz. Start the lesson to answer it and track your progress.
All lessons in Models and the Admin
1Your First Model
Your First ModelField Types
Defaults and Empty FieldsChoicesHow a Book PrintsDefault Order2Querying with the ORM
Creating RowsAll and GetFilter and LookupsCounting RowsSorting RowsUpdate and DeletePractice on your own: Django playground