Question

有没有办法在调用查询集的序列化程序中创建自定义字段？这是我想要做的：

我有一个Employee的序列化程序，我希望包含“last_attendance”字段。

 cols_to_convert <- colnames(dt)
 data.table::setDT(dt)[, (cols_to_convert) := lapply(.SD, as.numeric), .SDcols = cols_to_convert ]

我想再添加一个字段“last_attendance”。这是一个像这样的查询集：

class EmployeeSerializer(serializers.ModelSerializer):
    class Meta:
        model = Employee
        fields = ("id", 
                    "username", 
                    "first_name",
                    "last_name")

更新：

对于您的信息，我试图在此REST api中使用EmployeeSerializer

"last_attendance" = Attendance.objects.filter(employee_id = id_of_that_employee).last()

更新：

我发现SO可能有用，但还没有弄清楚如何应用Django Rest Framework - How to add custom field in ModelSerializer

Answer 1

使用MethodField：

class EmployeeSerializer(serializers.ModelSerializer):
    last_attendance = serializers.SerializerMethodField()
    class Meta:
        model = Employee
        fields = ("id", 
                    "username", 
                    "first_name",
                    "last_name",
                    "last_attendance")

    def get_last_attendance(self, obj):
        attendance = Attendance.objects.filter(employee_id = id_of_that_employee).last()
        if attendance:
            return attendance.date  # assuming it has this field
        else:
            return None

序列化程序自定义查询集字段

1 个答案: