模型中的 Django 多态性

Question

我想为不同的玩家设置不同的运动像下面。有办法吗？

示例模型：

class Player(models.Model):
    id          = models.AutoField(primary_key=True)
    sportType   = models.CharField(max_length=15)
    sportObj    = generic.GenericForeignKey('content_type')

class Icehockey(models.Model):
    id           = models.AutoField(primary_key=True)
    stick_brand  = models.CharField(max_length=50)
    skate_number = models.IntegerField()

class Basketball(models.Model):
    id           = models.AutoField(primary_key=True)
    ball_brand   = models.CharField(max_length=50)
    uniform_color= models.CharField(max_length=10)

class Football(models.Model):
    id           = models.AutoField(primary_key=True)
    shoeNumber   = models.IntegerField()
    uniform_size = models.CharField(max_length=10)

用法示例：

player1 = Player.objects.get(id=1).sportObj // returns <Icehockey object>
player2 = Player.objects.get(id=2).sportObj // returns <Basketball object>
player3 = Player.objects.get(id=3).sportObj // returns <Football object>
player4 = Player.objects.get(id=4).sportObj // returns <Football object>

编辑：如果有人需要，Django 网站上有一份关于 How content types works 的文档。

Answer 1

我觉得你提供的例子没问题，我对模型做了一些修改以使其可用。

from django.contrib.contenttypes.fields import GenericForeignKey
from django.contrib.contenttypes.models import ContentType
class Player(models.Model):
    SPORT_CHOICES = (
        ('I', 'Icehockey'),
        ('B', 'Basketball'),
        ('F', 'Football'),
        )
    sportType = models.CharField(max_length=15,choices=SPORT_CHOICES)
    sportObj = GenericForeignKey('content_type', 'object_id')
    object_id = models.PositiveIntegerField()
    content_type = models.ForeignKey(ContentType, on_delete=models.CASCADE)

class Icehockey(models.Model):
    stick_brand  = models.CharField(max_length=50)
    skate_number = models.IntegerField()

class Basketball(models.Model):
    ball_brand   = models.CharField(max_length=50)
    uniform_color= models.CharField(max_length=10)

class Football(models.Model):
    shoeNumber   = models.IntegerField()
    uniform_size = models.CharField(max_length=10)

模型中的 Django 多态性

Django polymorphism in model

django

polymorphism

database-design

django-models

relational-database