Field Type

Note

Documentation for blank and null can be found at Django blank and null

Attributes

blank

Documentation for blank can be found at Django blank and null

null

Documentation for null can be found at Django blank and null

verbose_name

From How can I get access to a Django Model field verbose name dynamically?:

from village.models import VillageModel
row = VillageModel.objects.all()[0]
row._meta.get_field_by_name('population')[0].verbose_name

Parameters

Name

Standard field types take an optional first positional argument that is the verbose name to use for that field e.g:

first_name = models.CharField("person's first name", max_length=30)

For the other field types (ForeignKey, ManyToManyField and OneToOneField) use the verbose_name keyword parameter:

poll = models.ForeignKey(Poll, verbose_name="the related poll")

editable

If False, the field will not be displayed in the admin or any other ModelForm. They are also skipped during model validation.

Default is True.

help_text

Extra “help” text to be displayed under the field on the object’s admin form.

primary_key

primary_key=True

Note: If Django sees you’ve explicitly set the primary_key, it won’t add the automatic id column.

unique

If True, this field must be unique throughout the table.

Note: Also see Meta, unique_together…

Types

BooleanField

models.BooleanField()

From Django 1.6, set default=False (if you want the default value to be False).

CharField

A string field, for small to large-sized strings.

Note: max_length is a required parameter e.g:

user = models.CharField(max_length=3)

To add a simple lookup:

COUNTRY_CHOICES = (
    ('ES', 'Spain'),
    ('FR', 'France'),
    ('UK', 'United Kingdom'),
)

country = models.CharField(max_length=2, choices=COUNTRY_CHOICES)

A field with choices will automatically get a get_FOO_display method.

DateTimeField

A date and time field.

created = models.DateTimeField(auto_now_add=True)
modified = models.DateTimeField(auto_now=True)

Every DateField and DateTimeField that does not have null=True, the object will have get_next_by_FOO and get_previous_by_FOO() methods, where FOO is the name of the field. This returns the next and previous object with respect to the date field, raising a DoesNotExist exception when appropriate.

DecimalField

Has two required arguments:

  • max_digits is the maximum number of digits allowed in the number. Note that this number must be greater than or equal to decimal_places, if it exists.

  • decimal_places The number of decimal places to store with the number.

For example, to store numbers up to 999 with a resolution of 2 decimal places:

models.DecimalField(max_digits=5, decimal_places=2)

FileField (and ImageField)

To Set Django’s FileField to an existing file just set instance.field.name to the path of your file e.g:

class Document(models.Model):
    file = FileField(upload_to=get_document_path)
    description = CharField(max_length=100)

doc = Document()
doc.file.name = 'path/to/file'
doc.file
<FieldFile: path/to/file>

To save the original file name see Save

Note

Don’t forget to use <form enctype="multipart/form-data" method="post" action="."> in your form.

ForeignKey

artist = models.ForeignKey(Musician)

Generic Content Type Field

../applications/contenttypes

ImageField

Note

Prerequisites Install the Python Imaging Library (Python Imaging Library (PIL and pillow)).

Note

Don’t forget to use <form enctype="multipart/form-data" method="post" action="."> in your form.

Sample

sample_image_field

class Person(models.Model):
    name = models.CharField(maxlength = 30)
    headshot = models.ImageField(upload_to='pictures')

To use in a template:

{{ object.headshot.url }}

ManyToManyField

See ManyToManyField…

OneToOneField

A one-to-one relationship. Conceptually, this is similar to a ForeignKey with unique=True, but the “reverse” side of the relation will directly return a single object:

class Car(models.Model):
    engine = models.OneToOneField(Engine)

>>> from testapp.models import Car, Engine
>>> c = Car.objects.get(name='Audi')
>>> e = Engine.objects.get(name='Diesel')
>>> e.car
<Car: Audi>

SlugField

slug = models.SlugField(unique=True)

Note:

The default value for max_length is 50.

A SlugField is supposed to create a unique index for this field, but it doesn’t seem to unless you put unique=True.

To auto-populate the slug field add the following to the admin object:

class ClubAdmin(admin.ModelAdmin):
    prepopulated_fields = {'slug':('name',),}

TextField

A large text field.

The admin represents this as a <textarea> (a multi-line input).

URLField

A field for a URL. If the verify_exists option is False (default), the URL will NOT be checked for existence.

UUIDField

import uuid

id = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False)