<XXX> 需要为字段 xxx 赋值才能使用此多对多关系

Question

我目前有以下3款

class modelToolName(models.Model):
    tool_name = models.CharField(max_length=250,unique=True)

class modelBodyPart(models.Model):
    part_name = models.CharField(max_length=128,unique=True)

class modelNormalBodyPartResult(models.Model):
    body_part = models.ForeignKey(modelBodyPart, default=None)
    tool_name = models.ManyToManyField(modelToolName, default=None, blank=True)
    result = models.TextField(blank=True, null=True)

现在我正尝试以这种方式将值插入 modelNormalBodyPartResult

result="xxxx"
bodpart = modelBodyPart.objects.get(part_name="xxx") #--->returns object fine
toolqset = modelToolName.objects.get(tool_name="xxx")#--->returns object fine
modelNormalBodyPartResult.objects.create(body_part=bodpart,tool_name = toolqset,result=result) --->error

我收到错误

<modelNormalBodyPartResult: modelNormalBodyPartResult object> needs to have a value for field "modelnormalbodypartresult" before this many-to-many relationship can be used.

我查看了 this post，但仍然无法解决问题。如有任何建议，我们将不胜感激。

Answer 1

您必须先创建一个对象，然后将ManyToMany个相关对象添加到其中，

result="xxxx"
bodpart = modelBodyPart.objects.get(part_name="xxx")
toolqset = modelToolName.objects.get(tool_name="xxx")
item = modelNormalBodyPartResult.objects.create(body_part=bodpart,result=result)
item.tool_name.add(toolqset)
item.save()

<XXX> 需要为字段 xxx 赋值才能使用此多对多关系

<XXX> needs to have a value for field xxx before this many-to-many relationship can be used

django

many-to-many

django-orm