![]() ![]() StringRelatedField may be used to represent the target of the relationship using its _str_ method.įor example, the following serializer: class AlbumSerializer(serializers. Return '%d: %s' % (self.order, self.title) class Album(models.Model):Īlbum_name = models.CharField(max_length=100)Īrtist = models.CharField(max_length=100)Īlbum = models.ForeignKey(Album, related_name='tracks', on_delete=models.CASCADE) Our models will be for music albums, and the tracks listed on each album. In order to explain the various types of relational fields, we'll use a couple of simple models for our examples. Owner = PrimaryKeyRelatedField(queryset=()) Name = CharField(allow_blank=True, max_length=100, required=False) Id = IntegerField(label='ID', read_only=True) To do so, open the Django shell, using python manage.py shell, then import the serializer class, instantiate it, and print the object representation… > from rializers import AccountSerializer Inspecting these automatically generated fields can be a useful tool for determining how to customize the relationship style. ![]() When using the ModelSerializer class, serializer fields and relationships will be automatically generated for you. Optimizing the queryset passed to AlbumSerializer with: qs = _related('tracks') If AlbumSerializer is used to serialize a fairly large queryset with many=True then it could be a serious performance problem. Print(AlbumSerializer(qs, many=True).data) # For each album object, tracks should be fetched from database It is the programmer's responsibility to optimize queries to avoid additional database hits which could occur while using such a serializer.įor example, the following serializer would lead to a database hit each time evaluating the tracks field if it is not prefetched: class AlbumSerializer(serializers.ModelSerializer):įields = A serializer with a field spanning an orm relation through its source attribute could require an additional database hit to fetch related objects from the database. Note: REST Framework does not attempt to automatically optimize querysets passed to serializers in terms of select_related and prefetch_related since it would be too much magic. Note: The relational fields are declared in relations.py, but by convention you should import them from the serializers module, using from rest_framework import serializers and refer to fields as serializers. They can be applied to ForeignKey, ManyToManyField and OneToOneField relationships, as well as to reverse relationships, and custom relationships such as GenericForeignKey. Relational fields are used to represent model relationships. Any suggestions? Thank you.Data structures, not algorithms, are central to programming. Unfortunately when I add this nothing appears in the framework once these have been added. Num_quizzes_passed = serializers.ReadOnlyField(source="get_quizzes_passed_count")įields = ('todo_count', 'discussion_count', 'num_quizzes_passed', 'username') class ProfileSerializer(serializers.HyperlinkedModelSerializer): I then added your suggestion to my ProfileSerializer. Return self.quiz_parent.filter(percent_correct_gte=0.8).count() I extended the User model and added a model method like you suggested. Quiz_passed = serializers.SerializerMethodField()įields = ('todo_count', 'discussion_count', 'quiz_passed', 'username', ) Todo_count = serializers.IntegerField(source='todo_unt', read_only=True)ĭiscussion_count = serializers.IntegerField(source='comment_unt', read_only=True) Here is my serializer: class ProfileSerializer(serializers.HyperlinkedModelSerializer): Percent_correct = models.FloatField(validators=)ĭate = models.DateTimeField(auto_now_add=True) User = models.ForeignKey(User, related_name='quiz_parent') Here is my QuizResult model: class QuizResult(models.Model): I want to be able to grab the percent_correct field of the model and do a calculation and add it to a field in the serializer called "quiz_passed". Viewed 684 times 0 Im searching for a solution to create a serializer / API Endpoint to represent data in a custom order. So far I don't have much idea on how to do so. Custom Serializer for Django Rest Framework. I would then duplicate the method to count the failed quizzes (under. I want to be able to look into the Users QuizResult and count the number of passed quizzes(.7 or over). I'm trying to create a custom serializer method that counts the number of passed and failed quizzes from my QuizResults model. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |