[英]Django REST Framework — Serializing many-to-many table relationships
我正在為一個網站創建一個API,我有一個帶有Books的表,另一個帶有Hashtags(基本上是一個主題標簽的目錄,例如“#traveling”)和一個用於建立書籍之間多對多關系的中間表和Hashtags。 我的模特是:
# models.py
class Books(models.Model):
id_books = models.AutoField(primary_key=True)
title = models.CharField(max_length=150)
class Hashtags(models.Model):
id_hashtags = models.AutoField(primary_key=True)
hashtag = models.CharField(max_length=150)
class Books_Hashtags(models.Model):
id_books_hashtags = models.AutoField(primary_key=True)
id_books = models.ForeignKey(Books, on_delete=models.CASCADE)
id_hashtags = models.ForeignKey(Hashtags, on_delete=models.CASCADE)
class Meta:
unique_together = ("id_books", "id_hashtags")
我想要一個提供如下輸出的API:
[
{
"id_books": 1,
"title": "The Hobbit",
"hashtags": [
{
"id_hashtags": 1,
"hashtag": "fantasy"
},
{
"id_hashtags": 2,
"hashtag": "fiction"
},
{
"id_hashtags": 3,
"hashtag": "middle earth"
},
]
}
]
為此,我按照我在網上找到的一些例子,使用DRF序列化了上面的模型:
#serializers.py
from rest_framework import serializers
from app.models import Books, Books_Hashtags, Hashtags
class HashtagsSerializer(serializers.ModelSerializer):
hashtags = serializers.CharField()
class Meta:
model = Hashtags
fields = ('hashtag',)
class Books_HashtagsSerializer(serializers.ModelSerializer):
id_hashtag = HashtagsSerializer(many=True, read_only=True)
class Meta:
model = Books_Hashtags
fields = ('id_hashtags',)
class BooksSerializer(serializers.ModelSerializer):
id_books = serializers.IntegerField()
id_books_hashtags = Books_HashtagsSerializer(many=True, read_only=True)
title = serializers.CharField()
class Meta:
model = Books
fields = ('id_books', 'title', 'id_books_hashtags',)
我的觀點如下:
#views.py
from ntgBackend.models import Books
from rest_framework import viewsets
from api.serializers import BooksSerializer
class BooksViewSet(viewsets.ModelViewSet):
serializer_class = BooksSerializer
queryset = Books.objects.all()
到目前為止,我已經設法從API獲得以下輸出:
[
{
"id_books": 1,
"title": "The Hobbit",
}
]
但是沒有關於主題標簽的信息,我知道它們存在於數據庫中。 我正在使用DRF 3.8.2與MySQL DB和Django 2.0.2。 請幫忙!
我遇到了同樣的問題,並通過一些研究得到了以下內容:
在models.py中,只使用Books_Hashtagas作為中間表,修改Book模型以包含帶有Hashtags的ManyToManyField。 另外,請務必在第一冊之前聲明您的Hashtag模型以供參考
# models.py
class Books(models.Model):
id_books = models.AutoField(primary_key=True)
title = models.CharField(max_length=150)
hashtags = models.ManyToManyField(Hashtags, related_name='hashTg', through="Books_Hashtags"
在序列化程序文件中,請確保添加depth = 1以獲得所需內容,否則您將只獲取#標簽ID(僅適用於ListAPI)
#serializers.py
class BooksSerializer(serializers.ModelSerializer):
class Meta:
model = Books
#In case you want to filter out some fields:
#fields = ('field_A','field_B' )
fields = '__all__'
depth = 1
在視圖中我使用泛型,因為它們解決了我的大多數需求:
#views.py
from ntgBackend.models import Books
from rest_framework import generics
from api.serializers import BooksSerializer
class BooksViewSet(generics.ListCreateAPIView):
serializer_class = BooksSerializer
queryset = Books.objects.all()
我對此很陌生,我希望它有所幫助。 除了Django(2.0.4)之外,我使用的版本與你幾乎相同。
祝好運
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