Question

您好我在我的Tastypie项目中使用Django。当我获取与资源api中的其他模型具有外键关系的模型值时，其返回空值。

我使用MySql作为我的数据库。

我的型号代码：

TopicDetail模型

class Topicdetails(models.Model):
    apptopicid = models.IntegerField(db_column='appTopicID', primary_key=True) # Field name made lowercase.
    portaltopicid = models.IntegerField(db_column='portalTopicID', blank=True, null=True) # Field name made lowercase.
    topicname = models.CharField(db_column='topicName', max_length=500, blank=True) # Field name made lowercase.
    topicshortdescription = models.CharField(db_column='topicShortDescription', max_length=5000, blank=True) # Field name made lowercase.
    class Meta:
        managed = False
        db_table = 'TopicDetails'

Instructor Detail模型

class Instructordetails(models.Model): 
    appinstructorid = models.IntegerField(db_column='appInstructorID', primary_key=True) # Field name made lowercase.
    portalinstructorid = models.IntegerField(db_column='portalInstructorID') # Field name made lowercase.
    firstname = models.CharField(db_column='firstName', max_length=50, blank=True) # Field name made lowercase.
    middlename = models.CharField(db_column='middleName', max_length=50, blank=True) # Field name made lowercase.
    lastname = models.CharField(db_column='lastName', max_length=50, blank=True) # Field name made lowercase.
    optionalid = models.IntegerField(db_column='optionalID', blank=True, null=True) # Field name made lowercase.
    class Meta:
        managed = False
        db_table = 'InstructorDetails'

TopicInstructor模型，其中两个模型有两个外键。

class Topicinstructor(models.Model):
    topicinstructorrelationid = models.IntegerField(db_column='topicInstructorRelationID', primary_key=True) # Field name made lowercase.
    apptopicid = models.ForeignKey(Topicdetails, db_column='appTopicID') # Field name made lowercase.
    appinstructorid = models.ForeignKey(Instructordetails, db_column='appInstructorID') # Field name made lowercase.
    class Meta:
        managed = False
        db_table = 'TopicInstructor'

我的TopicInstructor api代码：

class TopicinstructorResource(ModelResource):
    # topicdetails = fields.ForeignKey(TopicdetailsResource,'topicdetails')
    #instructordetails = fields.ForeignKey(InstructordetailsResource, 'instructordetails')
    class Meta:
        queryset = Topicinstructor.objects.all()
        resource_name = 'topicinstructor'
        include_resource_uri = False

如果我在我的资源api上面两行代码注释，则显示错误：

{
error: "The model '&lt;Topicinstructor: Topicinstructor object&gt;' has an empty attribute 'instructordetails' and doesn't allow a null value."
}

如果获取资源，它返回输出如下：

{
meta: {
    limit: 20,
    next: "/api/topicinstructor/?offset=20&limit=20&format=json",
    offset: 0,
    previous: null,
    total_count: 994
    },
objects: [
    {
        topicinstructorrelationid: 1
    },
    {
        topicinstructorrelationid: 2
    },
    {
        topicinstructorrelationid: 3
    },
    {
        topicinstructorrelationid: 4
    },
  ]
}

但我还需要获取外键值。更多内容我使用python manage.py inspectdb命令从MySql数据库创建了我的模型文件。

请帮助我......

Answer 1

将null=True放置为允许空值

topicdetails = fields.ForeignKey(TopicdetailsResource,'topicdetails',null=True)
 instructordetails = fields.ForeignKey(InstructordetailsResource,'instructordetails',null=True)

如何使用TastyPie在REST Api中获取外键值？

1 个答案: