python - 当从遗留数据库生成模型类时，如何在 django-rest 中序列化多个模型数据

Question

1. 模型类是从现有数据库生成的，生成的模型类中不显示外键关系。

   $ python manage.py inspectdb
   
   $ python manage.py inspectdb > models.py
   

2. 目标是从多个表中获取相关数据。

3. 以下是我的序列化器片段:

   from .models import JobsList, JobsCategories
   class JobsCategoriesSerializer(serializers.ModelSerializer):
   class Meta:
       model = JobsCategories
       fields = ('name', 'id',)
   
   class JobsListSerializer(serializers.ModelSerializer):
       category = JobsCategoriesSerializer(source='job_category', many=True)
       class Meta:
           model  = JobsList
           fields = ('job_title', 'category')
   

4. 错误:请求方式:GET请求网址:http://localhost:8000/jobs/6/?access_token=bBN6BSLlYi8TXF3SkLEOMbtsKfD3xX&format=jsonDjango 版本:1.8.3异常类型:TypeError异常值:

   “长”对象不可迭代

5.1 响应为:

{"id":6,"userid":491,"company_id":4,"job_title":"Web Designer","job_info":"We require a web designer.","min_exp":0,"max_exp":1,"min_ctc":null,"max_ctc":null,"open_positions":0,"location":"18","hr_email":"","contact_number":"","job_category":3,"job_referred":"0","added_by":"0","status":"1","date_time":null,"expiry_date":null,"job_meta":"web graphics bodhan designer funvestfinancials","job_type":"0"}

** 我想要 job_category，它是一个用类别名称替换的 id**

我需要帮助获取带有作业数据的类别名称 jobs_category 和 jobs_list 是通过现有数据库的逆向工程生成的两个单独的模型类。如果我正在做的这种方式可行或者其他方式可行，请帮助我。

职位列表模型:

class JobsList(models.Model):
    .....
    job_category    = models.IntegerField(blank=True, null=True)
    .....

类别模型:

class JobsCategories(models.Model):
   name = models.CharField(max_length=255)
   status = models.CharField(max_length=1)

   class Meta:
        managed = False
        db_table = 'jobs_categories'

    def __unicode__(self):
         return '%s' % (self.name)

** 我需要类别名称，其 id 在 job_category 列 jobs_list 表中。问题是从遗留数据库生成的模型类没有关系**

Answer 1

您可以覆盖 to_representation() JobsListSerializer 的方法来获取您想要的响应。

您需要执行以下操作:

class JobsListSerializer(serializers.ModelSerializer):
    class Meta:
        model  = JobsList
        ...

    def to_representation(self, obj):
        serialized_data = super(JobsListSerializer, self).to_representation(obj) # original serialized data
        job_category_id = serialized_data.get('job_category') # get job category id from original serialized data
        job_category = JobsCategories.objects.get(id=job_category_id) # get the object from db
        serialized_data['job_category'] = job_category.name # replace id with category name
        return serialized_data # return modified serialized data