如何在Django-rest-framework serializer中的关系模型中获得额外的列? [英] How to get an extra column in relational model in Django-rest-framework serializer?
问题描述
我有类别
和文章
模型,文章
在我的序列化程序
中有一个外键引用类别
我可以在Category模型中获取名称列,因为_ code> _str __ 方法,但如何获取类别
中的其他列?
I have Category
and Article
model,Article
has a foreign key reference Category
,in my serializer
i can get the name column in Category model because of the __str__
method,but how can i get other columns in Category
model
models.py:
models.py:
# blog category models
class Category(models.Model):
#id = models.IntegerField(primary_key=True,help_text='primary key',auto_created=True)
name = models.CharField(max_length=50,help_text='category name')
description = models.TextField(default='',help_text='category description')
coverimg = models.CharField(max_length=200,default='',help_text='category front cover image')
covercolor = models.CharField(max_length=7,default='#ffffff',help_text='color for each category background')
totalitems = models.IntegerField(default=0,help_text='total items for each category')
createtime = models.DateTimeField(auto_now_add=True)
modifytime = models.DateTimeField(auto_now=True)
categories = models.Manager()
class Meta:
db_table = 'article_category'
def __str__(self):
return self.name
#blog article models
class Article(models.Model):
STATUS = (
(0,'on'),
(1,'off')
)
#id = models.IntegerField(primary_key=True,help_text='primary key',auto_created=True)
category = models.ForeignKey(Category,related_name='articles', help_text='foreigner key reference Category')
#author = models.ForeignKey(myadmin.User, help_text='foreigner key reference myadmin User')
title = models.CharField(max_length=100, help_text='article title')
description = models.TextField(help_text='article brief description')
content = models.TextField(help_text='article content')
like = models.IntegerField(default=0,help_text='like numbers')
secretcode = models.CharField(max_length=512,help_text='who has the code can scan')
status = models.IntegerField(choices=STATUS,help_text='status of the article')
createtime = models.DateTimeField(auto_now_add=True,help_text='time that first created')
modifytime = models.DateTimeField(auto_now=True,help_text='time when modified')
articles = models.Manager()
def __str__(self):
return self.title
class Meta:
db_table = 'article'
def save(self, *args, **kwargs):
if not self.id:
Category.categories.filter(pk=self.category.pk).update(totalitems = F('totalitems')+1)
super(Article,self).save(*args, **kwargs)
serializers.py:
serializers.py:
# Article catalog
class ArticleCatalogSerializer(serializers.ModelSerializer):
category = serializers.StringRelatedField()
articletags = serializers.StringRelatedField(many=True)
covercolor = serializers.StringRelatedField()
class Meta:
model = Article
fields = ('id', 'title', 'category', 'articletags', 'description', 'like', 'createtime', 'covercolor')
covercolor = serializers.StringRelatedField()会导致错误:文章'对象没有属性'covercolor
,我更改为:
covercolor = serializers.StringRelatedField() would cause an error:Article' object has no attribute 'covercolor
and i changed to this :
已更改serializers.py:
# category serializer for ArticleCatalogSerializer for nested relationship
class CategoryNestedRelationshipSerializer(serializers.ModelSerializer):
class Meta:
model = Category
fields = ('covercolor',)
# Article catalog
class ArticleCatalogSerializer(serializers.ModelSerializer):
category = serializers.StringRelatedField()
articletags = serializers.StringRelatedField(many=True)
covercolor = CategoryNestedRelationshipSerializer(read_only=True)
class Meta:
model = Article
ields = ('id', 'title', 'category', 'articletags', 'description', 'like', 'createtime', 'covercolor')
发生错误:
Got AttributeError when attempting to get a value for field `covercolor` on serializer `ArticleCatalogSerializer`.
The serializer field might be named incorrectly and not match any attribute or key on the `Article` instance.
Original exception text was: 'Article' object has no attribute 'covercolor'.
如何实现?
推荐答案
在您的编辑中,将ArticleCatalogSerializer更改为
In your edit , Change your ArticleCatalogSerializer to
class ArticleCatalogSerializer(serializers.ModelSerializer):
category = CategoryNestedRelationshipSerializer()
class Meta:
model = Article
您将获得此格式的输出
{
"id": 1,
"category": {
"covercolor": "#ffffff"
},
"title": "sa",
"description": "bhjghj",
"content": "sda",
"like": 0,
"secretcode": "77",
"status": 0,
"createtime": "2015-04-18T07:52:57.230110Z",
"modifytime": "2015-04-18T07:52:57.230135Z"
}
如果你想要任何其他类别的列,你可以在你的类别序列化器中包含这样的
If you want any other column of category , you can include in your category serializer like this
class CategoryNestedRelationshipSerializer(serializers.ModelSerializer):
class Meta:
model = Category
fields = ('covercolor','name','description')
这篇关于如何在Django-rest-framework serializer中的关系模型中获得额外的列?的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!