mirror of https://github.com/django/django.git
166 lines
3.8 KiB
Python
166 lines
3.8 KiB
Python
"""
|
|
Serialization
|
|
|
|
``django.core.serializers`` provides interfaces to converting Django
|
|
``QuerySet`` objects to and from "flat" data (i.e. strings).
|
|
"""
|
|
from decimal import Decimal
|
|
|
|
from django.db import models
|
|
|
|
|
|
class CategoryMetaDataManager(models.Manager):
|
|
|
|
def get_by_natural_key(self, kind, name):
|
|
return self.get(kind=kind, name=name)
|
|
|
|
|
|
class CategoryMetaData(models.Model):
|
|
kind = models.CharField(max_length=10)
|
|
name = models.CharField(max_length=10)
|
|
value = models.CharField(max_length=10)
|
|
objects = CategoryMetaDataManager()
|
|
|
|
class Meta:
|
|
unique_together = (('kind', 'name'),)
|
|
|
|
def __str__(self):
|
|
return '[%s:%s]=%s' % (self.kind, self.name, self.value)
|
|
|
|
def natural_key(self):
|
|
return (self.kind, self.name)
|
|
|
|
|
|
class Category(models.Model):
|
|
name = models.CharField(max_length=20)
|
|
meta_data = models.ForeignKey(CategoryMetaData, models.SET_NULL, null=True, default=None)
|
|
|
|
class Meta:
|
|
ordering = ('name',)
|
|
|
|
def __str__(self):
|
|
return self.name
|
|
|
|
|
|
class Author(models.Model):
|
|
name = models.CharField(max_length=20)
|
|
|
|
class Meta:
|
|
ordering = ('name',)
|
|
|
|
def __str__(self):
|
|
return self.name
|
|
|
|
|
|
class Article(models.Model):
|
|
author = models.ForeignKey(Author, models.CASCADE)
|
|
headline = models.CharField(max_length=50)
|
|
pub_date = models.DateTimeField()
|
|
categories = models.ManyToManyField(Category)
|
|
meta_data = models.ManyToManyField(CategoryMetaData)
|
|
|
|
class Meta:
|
|
ordering = ('pub_date',)
|
|
|
|
def __str__(self):
|
|
return self.headline
|
|
|
|
|
|
class AuthorProfile(models.Model):
|
|
author = models.OneToOneField(Author, models.CASCADE, primary_key=True)
|
|
date_of_birth = models.DateField()
|
|
|
|
def __str__(self):
|
|
return "Profile of %s" % self.author
|
|
|
|
|
|
class Actor(models.Model):
|
|
name = models.CharField(max_length=20, primary_key=True)
|
|
|
|
class Meta:
|
|
ordering = ('name',)
|
|
|
|
def __str__(self):
|
|
return self.name
|
|
|
|
|
|
class Movie(models.Model):
|
|
actor = models.ForeignKey(Actor, models.CASCADE)
|
|
title = models.CharField(max_length=50)
|
|
price = models.DecimalField(max_digits=6, decimal_places=2, default=Decimal('0.00'))
|
|
|
|
class Meta:
|
|
ordering = ('title',)
|
|
|
|
def __str__(self):
|
|
return self.title
|
|
|
|
|
|
class Score(models.Model):
|
|
score = models.FloatField()
|
|
|
|
|
|
class Team(object):
|
|
def __init__(self, title):
|
|
self.title = title
|
|
|
|
def __str__(self):
|
|
raise NotImplementedError("Not so simple")
|
|
|
|
def to_string(self):
|
|
return "%s" % self.title
|
|
|
|
|
|
class TeamField(models.CharField):
|
|
|
|
def __init__(self):
|
|
super(TeamField, self).__init__(max_length=100)
|
|
|
|
def get_db_prep_save(self, value, connection):
|
|
return str(value.title)
|
|
|
|
def to_python(self, value):
|
|
if isinstance(value, Team):
|
|
return value
|
|
return Team(value)
|
|
|
|
def from_db_value(self, value, expression, connection, context):
|
|
return Team(value)
|
|
|
|
def value_to_string(self, obj):
|
|
return self.value_from_object(obj).to_string()
|
|
|
|
def deconstruct(self):
|
|
name, path, args, kwargs = super(TeamField, self).deconstruct()
|
|
del kwargs['max_length']
|
|
return name, path, args, kwargs
|
|
|
|
|
|
class Player(models.Model):
|
|
name = models.CharField(max_length=50)
|
|
rank = models.IntegerField()
|
|
team = TeamField()
|
|
|
|
def __str__(self):
|
|
return '%s (%d) playing for %s' % (self.name, self.rank, self.team.to_string())
|
|
|
|
|
|
class BaseModel(models.Model):
|
|
parent_data = models.IntegerField()
|
|
|
|
|
|
class ProxyBaseModel(BaseModel):
|
|
class Meta:
|
|
proxy = True
|
|
|
|
|
|
class ProxyProxyBaseModel(ProxyBaseModel):
|
|
class Meta:
|
|
proxy = True
|
|
|
|
|
|
class ComplexModel(models.Model):
|
|
field1 = models.CharField(max_length=10)
|
|
field2 = models.CharField(max_length=10)
|
|
field3 = models.CharField(max_length=10)
|