Question

我刚刚开始为Django开发并使用Django REST Framework和基于类的视图构建API。我正在寻找一种方法来组合模型，根据时间对它们进行排序，然后将字段的子集返回到附加了表名的API。

目前我有以下内容：

views.py

class RunLog(APIView):
        """
        List log for a specific run sorted in reverse chronological order
        """
        def get(self, request, run_id, format=None):
            # Combine and sort based on time (decreasing) 
            result_list = sorted(chain(Output.objects.filter(run=run_id),
                                       Downtime.objects.filter(run=run_id)), 
                                key=attrgetter('start_time'), reverse=True)

            // Replace this with serializer??
            response = Response(serializers.serialize('json', result_list), status=status.HTTP_200_OK)
            return response

models.py

class Output(models.Model):
    start_time = models.DateTimeField(default=datetime.now)
    value = models.FloatField()

    run = models.ForeignKey(Run, blank=True, null=True)

    def __unicode__(self):
        return str(self.id)

class Downtime(models.Model):
    start_time = models.DateTimeField(default=datetime.now)
    end_time = models.DateTimeField(null=True, blank=True)
    reason = models.CharField(max_length=500)

    run = models.ForeignKey(Run, blank=True, null=True)

我得到以下JSON：

"[{\"model\": \"app.downtime\", \"pk\": 91, \"fields\": {\"start_time\": \"2016-07-20T14:46:21Z\", \"end_time\": null, \"reason\": \"reason1\", \"run\": 71}}, {\"model\": \"app.downtime\", \"pk\": 101, \"fields\": {\"start_time\": \"2016-07-20T14:46:21Z\", \"end_time\": null, \"reason\": \"reason2\", \"run\": 71}}]"

我想用以下JSON格式序列化这些数据：

    [
        {
            "id": 231,
            "type": "speed",
            "description": "Some description",
            "time": "2016-07-21T21:26:26Z"
        }
    ]

**Where type is the database table and description is concatenated columns from a model.

我看过文档和this similar question没有任何运气。

Answer 1

正如IanAuld在评论中所建议的那样 - ModelObj._meta.db_table得到了表的名称。然后我在views.py中创建了一个排序的字典列表：

hdfs dfs -put opt/ibm/labfiles/README.md /user/root/input/tmp/

serializers.py：

speedList = Speed.objects.filter(run=run_id)
type = Speed._meta.db_table.split('_', 1)[1]
type = type[0].upper() + type[1:]

for speed in speedList:
    description = "Speed change to %.2f (units)" % speed.value
    logList.append({'id':speed.id, 'type':type, 'description':description, 'time':speed.start_time})

# Sort list by decreasing time
resultList= sorted(logList, key=itemgetter('time'), reverse=True)

serializer = LogSerializer(resultist, many=True)
return Response(serializer.data)

Django REST框架 - 没有模型的序列化视图

1 个答案: