DRF learning notes (III): model class serializer modelserializer

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Preface

When we have many models , Write a corresponding serializer for each model , It will be very inconvenient .DRF For us ModelSerializer Model class serializer to help us quickly create a Serializer class .

ModelSerializer And conventional Serializer identical , But provided ：

（1） Automatically generate a series of fields based on the model class
（2） Based on the model class, automatically create Serializer Generate validators, such as unique_together
（3） Contains the default create() and update() The implementation of the

One 、ModelSerializer Use

1、 stay demo/serializers Modify the ClassInfoSerializer

class ClassInfoSerializer(serializers.ModelSerializer):
    """ Class data serializer """
    # id = serializers.IntegerField(label='ID', read_only=True)
    # number = serializers.IntegerField(label=' Class number ', required=False)
    # grade = serializers.CharField(label=' grade ', max_length=3, required=False)
    # studentinfo_set = serializers.PrimaryKeyRelatedField(read_only=True, many=True) #  add to 
    class Meta:
        model = ClassInfo
        fields = '__all__'

result ：

>>> from demo.serializers import ClassInfoSerializer
>>> serializer = ClassInfoSerializer()
>>> serializer
ClassInfoSerializer():
    id = IntegerField(label='ID', read_only=True)
    number = IntegerField(label=' Class number ', max_value=2147483647, min_value=-2147483648)
    grade = ChoiceField(choices=((' In grade one ', ' In grade one '), (' second grade ', ' second grade '), (' Third grade ', ' Third grade ')), label=' grade ')

Two 、 Indicate field

1、 Use fields To define the fields ,__all__ The table name contains all the fields , You can also specify which fields , Such as ：

class ClassInfoSerializer(serializers.ModelSerializer):
    """ Class data serializer """
    class Meta:
        model = ClassInfo
        fields = ('number', 'grade')

result ：

>>> from demo.serializers import ClassInfoSerializer
>>> serializer = ClassInfoSerializer()
>>> serializer
ClassInfoSerializer():
    number = IntegerField(label=' Class number ', max_value=2147483647, min_value=-2147483648)
    grade = ChoiceField(choices=((' In grade one ', ' In grade one '), (' second grade ', ' second grade '), (' Third grade ', ' Third grade ')), label=' grade ')

2、 Use exclude Which fields can be explicitly excluded ：

class ClassInfoSerializer(serializers.ModelSerializer):
    """ Class data serializer """
    class Meta:
        model = ClassInfo
        exclude = ('id',)

result ：

>>> from demo.serializers import ClassInfoSerializer
>>> serializer = ClassInfoSerializer()
>>> serializer
ClassInfoSerializer():
    number = IntegerField(label=' Class number ', max_value=2147483647, min_value=-2147483648)
    grade = ChoiceField(choices=((' In grade one ', ' In grade one '), (' second grade ', ' second grade '), (' Third grade ', ' Third grade ')), label=' grade ')

3、 Default ModelSerializer Use the primary key as the associated field , But we can use depth To simply generate nested representations ,depth It should be an integer , Indicates the number of nested levels . Such as ：

class StudentInfoSerializer(serializers.ModelSerializer):
    """ Student data serializer """
    class Meta:
        model = StudentInfo
        fields = '__all__'
        depth = 1

There are no hierarchical results ：

>>> from demo.serializers import StudentInfoSerializer
>>> serializer = StudentInfoSerializer()
>>> serializer
StudentInfoSerializer():
    id = IntegerField(label='ID', read_only=True)
    name = CharField(label=' full name ', max_length=10)
    sex = ChoiceField(choices=((' male ', ' male '), (' Woman ', ' Woman ')), label=' Gender ')
    from_class = PrimaryKeyRelatedField(queryset=ClassInfo.objects.all())

Hierarchical results ：

>>> from demo.serializers import StudentInfoSerializer
>>> serializer = StudentInfoSerializer()
>>> serializer
StudentInfoSerializer():
    id = IntegerField(label='ID', read_only=True)
    name = CharField(label=' full name ', max_length=10)
    sex = ChoiceField(choices=((' male ', ' male '), (' Woman ', ' Woman ')), label=' Gender ')
    from_class = NestedSerializer(read_only=True):
        id = IntegerField(label='ID', read_only=True)
        number = IntegerField(label=' Class number ', max_value=2147483647, min_value=-2147483648)
        grade = ChoiceField(choices=((' In grade one ', ' In grade one '), (' second grade ', ' second grade '), (' Third grade ', ' Third grade ')), label=' grade ')

3、 ... and 、 Add extra parameters

We can use extra_kwargs Parameter is ModelSerializer Add or modify the original option parameters ：

class ClassInfoSerializer(serializers.ModelSerializer):
    """ Class data serializer """
    class Meta:
        model = ClassInfo
        exclude = ('id',)
        extra_kwargs = {
    
            'number': {
    'min_value': 0}

result ：

>>> from demo.serializers import ClassInfoSerializer
>>> serializer = ClassInfoSerializer()
>>> serializer
ClassInfoSerializer():
    number = IntegerField(label=' Class number ', max_value=2147483647, min_value=0)
    grade = ChoiceField(choices=((' In grade one ', ' In grade one '), (' second grade ', ' second grade '), (' Third grade ', ' Third grade ')), label=' grade ')

That's all for serialization , The next chapter will talk about DRF View content of
Next chapter ：DRF Learning notes ( Four )：DRF View