Python 如何使用TastyPie在RESTAPI中获取外键值？

您好，我正在将

tastype

与我的

Django

项目一起使用。当我在resource

api

中获取与其他模型有外键关系的模型值时，它返回空值

我使用MySql作为我的数据库

我的型号代码：

TopicDetail

Model

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'

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'

讲师详细信息

型号

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'

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

Model，它具有上述两种型号中的两个外键

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'

和我的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

如果我从我的资源api中取消注释以上两行代码，则显示错误：

{
error: "The model '<Topicinstructor: Topicinstructor object>' has an empty attribute 'instructordetails' and doesn't allow a null value."
}

如果获取资源，则返回如下输出：

{
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
    },
  ]
}

但是我还需要获取外键值。更多信息，我使用

python manage.py inspectdb

命令从MySql数据库创建了模型文件

---

请帮助我……

将

null=True

设置为允许空值

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

---

如果我根据您的建议添加或修改代码，它会将所有对象返回为null。但我的数据库有价值。对于修改对象后的示例输出：[{instructordetails:null，topicdetails:null，topicinstructorrelationid:1}，]如果我的外键引用为null，我不会得到

，这意味着我提到了我的问题“TopicInstructor”不会包含任何null字段。@Nagarajan我想你将null=True仅用于讲师详细信息，try只需要从中获取两个
apptopicid
form
topicdetails
model和
appinstructorid
instructor详细信息
model。对于此输出，我必须在代码中进行哪些更改