Question

我正在进入PHP到Django的迁移项目，我无法更改数据库的模式

对于没有FK的字段，有些地方存在多个连接，我现在无权添加它们。即使在我的Django模型上，由于数据库的庞大规模和项目交付的时间限制。

我正在使用Django-rest-framework并重写list方法和queryset来接受这些原始sqls。

sql = """SELECT
  a.field1,
  b.field2
FROM a
LEFT JOIN b ON a.fieldx = b.fieldy"""

问题是我无法在字段元组内的序列化器类中添加连接表的字段因为我说模型= models.A而且这个模型没有关于模型B的信息。

我们将不胜感激。

谢谢！

UPDATE 我只使用viewset。我没有使用任何视图（这是错的吗？）我的观点

class AdminclassinfoViewSet(viewsets.ModelViewSet): 
    queryset = models.Classroominfo.objects.all()
    serializer_class = ClassroominfoSerializer

    def list(self, request):
       sql = """
         SELECT -- DISTINCT 
           cri.classroomid,
           cri.assessmentid, 
           cri.resourceid,
           al.assessmenttype,
           al.assessmenttitle,
           ri.resourcetype,
           ri.resourcetitle,
           wwi.writtenworktitle,
           cri.writtenworkid, 
           si.firstname,
           si.imageurl,
           date(cri.posteddate) as posteddate,
           cri.studentid
       FROM classroominfo cri
       LEFT OUTER JOIN assignassessmentinfo aai ON aai.assessmentid = cri.assessmentid 
                   AND aai.studentid = cri.studentid 
       LEFT OUTER JOIN assessmentlist al ON al.assessmentid = cri.assessmentid 
       LEFT OUTER JOIN assignresourceinfo ari  ON ari.resourceid = cri.resourceid 
                  AND ari.studentid = cri.studentid 
       LEFT OUTER JOIN resourceinfo ri ON ri.resourceid = cri.resourceid
       LEFT OUTER JOIN assignwrittenworkinfo awwi ON awwi.writtenworkid = cri.writtenworkid
       LEFT OUTER JOIN writtenworkinfo wwi ON wwi.writtenworkid = cri.writtenworkid
       LEFT OUTER JOIN logininfo li ON li.loginid = cri.studentid
       LEFT OUTER JOIN studentinfo si ON si.username = li.username
       WHERE ( ari.isclassroom =1 OR 
             aai.isclassroom =1 OR 
            awwi.isclassroom=1 ) 
       ORDER BY cri.classroomid DESC
       """
       queryset = models.Classroominfo.objects.raw(sql)
       serializer_class = ClassroominfoSerializer
       serializer = ClassroominfoSerializer(queryset, many=True)        
       return Response(serializer.data)

我的序列化程序。我不知道如何在这里引用加入的字段......

class ClassroominfoSerializer(serializers.ModelSerializer):
    class Meta:
        model = models.Classroominfo
        fields = ('classroomid',  'assessmentid','resourceid',
              'writtenworkid')

Answer 1

由于我处于截止日期，我恢复运行queries directly并转换为dicts列表并从我的listset方法组返回，如下所示：

desc = cursor.description
result =  [
            dict(zip([col[0] for col in desc], row))
            for row in cursor.fetchall()
    ]
return Response(result)

它仍然使用Django Rest API接口，因此对我来说，偶尔使用硬编码的sql查询并不是什么大问题。

但是，如果Django Rest Framework 3.x可以灵活处理这种用例，我将不胜感激。

Answer 2

因此，根据您的SQL查询，似乎classroominfo表位于某种星型模式的中心。您应该可以使用“深度”属性来包含nested serializations。

class ClassroominfoSerializer(serializers.ModelSerializer):
    class Meta:
        model = models.Classroominfo
        fields = ('classroomid',  'assessmentid','resourceid', 'writtenworkid')
        depth = 2

在Django-rest-framework中加入表字段

2 个答案: