【发布时间】：2019-03-28 23:02:27
【问题描述】：
我正在开发一个基于 django 的后端。
我有一个子导师模型。这个模型将有一个 list 与它相关的 names。所以，我制作了一个名为List的模型。他们都有多对多关系。现在，我制作了另一个名为 names 的模型。这与 List 具有 ManytoMany 关系。该列表将有许多名称。每个子导师都有一个列表。
编码后，当我尝试在管理控制台的列表中添加一个值时，我得到 core.Name.none 而不是我的子导师列表中的名称。
我做错了什么？
模型代码：-
class Names(models.Model):
user = models.OneToOneField(User,on_delete=models.CASCADE,blank=True,null=True)
name = models.CharField(max_length=50)
def __str__(self):
return self.name
class SAccepted_list(models.Model):
saccepted_name = models.ManyToManyField(Names,blank =True, related_name='saccepted_name')
def __str__(self):
return str(self.saccepted_name)
class SPending_list(models.Model):
spending_name = models.ManyToManyField(Names,blank =True, related_name='spending_name')
def __str__(self):
return str(self.spending_name)
class SRejected_list(models.Model):
srejected_name = models.ManyToManyField(Names,blank =True, related_name='srejected_name')
def __str__(self):
return str(self.srejected_name)
class SubMentor(models.Model):
user = models.OneToOneField(User, on_delete=models.CASCADE, primary_key=True)
mentee_pref_count = models.IntegerField(default=3, verbose_name='Preferred mentee count')
rating = GenericRelation(Rating, related_query_name='Submentor')
skills = models.ManyToManyField(Skill, blank=True, related_name='subskills')
courses = models.ManyToManyField(Course, blank=True, related_name='subcourses')
projects = models.ManyToManyField(Project, blank=True, related_name='subprojects')
saccepted_list = models.ManyToManyField(SAccepted_list,blank=True,related_name='saccepted_list')
spending_list = models.ManyToManyField(SPending_list, blank=True,related_name='spending_list')
srejected_list = models.ManyToManyField(SRejected_list, blank=True,related_name='srejected_list')
def __str__(self):
return self.user.get_full_name()
def get_mentee_count(self, *args, **kwargs):
if self.trainees.exists():
return self.trainees.count()
else:
return 0
class Accepted_list(models.Model):
accepted_name = models.ManyToManyField(Names,blank =True, related_name='accepted_name')
# saccepted_name = models.ManyToManyField(Names,blank =True, related_name='saccepted_name')
def __str__(self):
return str(self.accepted_name)
class Pending_list(models.Model):
pending_name = models.ManyToManyField(Names,blank =True, related_name='pending_name')
# spending_name = models.ManyToManyField(Names,blank =True, related_name='spending_name')
def __str__(self):
return str(self.pending_name)
class Rejected_list(models.Model):
rejected_name = models.ManyToManyField(Names,blank =True, related_name='rejected_name')
# srejected_name = models.ManyToManyField(Names,blank =True, related_name='srejected_name')
def __str__(self):
return str(self.rejected_name)
class Mentor(models.Model):
user = models.OneToOneField(User, on_delete=models.CASCADE, primary_key=True)
score = models.FloatField(default=0, blank=True, null=True)
mentee_pref_count = models.IntegerField(default=5, verbose_name='Preferred menteee count')
rating = GenericRelation(Rating, related_query_name='mentor')
skills = models.ManyToManyField(Skill, blank=True, related_name='skills')
accepted_list = models.ManyToManyField(Accepted_list,blank=True,related_name='accepted_list')
pending_list = models.ManyToManyField(Pending_list, blank=True,related_name='pending_list')
rejected_list = models.ManyToManyField(Rejected_list, blank=True,related_name='rejected_list')
def __str__(self):
return self.user.get_full_name()
def get_mentee_count(self, *args, **kwargs):
if self.trainees.exists():
return self.trainees.count()
else:
return 0
我直接通过管理控制台添加名称的图片：-
谢谢。
【问题讨论】：
-
这个设置真的没有任何意义。您获得该值是因为您的支出列表 m2m 字段指向 SPending_list 模型，并且该模型上唯一的东西是 another m2m 到名称； SPending_list 上的
__str__方法使用该 m2m 生成字符串以在选择框中显示，但没有选择任何内容，因此它所能做的就是打印“无”。但实际上，拥有一个指向另一个 m2m 的 m2m 绝对不是您想要做的。 -
哦，那我该怎么办？我刚刚开始学习 django，感谢您的帮助。 @丹尼尔罗斯曼
标签： python django model backend web-development-server