Django rest api筛选错误消息:Django.core.exceptions.Field error:相关字段的查找无效

MainName 会过滤掉 Profile 使用此查询:

Profile.objects.all().filter(simmatch__mainname__mainname=name.lower())

但我收到一条错误信息:

django.core.exceptions.FieldError:相关字段的查找无效:mainname

有人能告诉我我做错了什么吗?我对Django很陌生。谢谢!

我的模型:

class Profile(models.Model):
    ID = models.IntegerField(unique=True, primary_key=True)
    name = models.CharField(max_length=200)
    hasArticle       = models.CharField(max_length=3)
    gender_guessed   = models.CharField(max_length=5)
    age              = models.CharField(max_length=5)
    profile = models.TextField()

    def __str__(self):
        return "{}".format(self.name)

class MainName(models.Model):
    ID = models.IntegerField(unique=True, primary_key=True)
    mainName = models.CharField(  max_length=100) 

    def __str__(self):
        return "{}".format(self.mainName)


class SimMatch(models.Model):
    profile = models.ForeignKey(Profile,to_field="ID", db_column="profile_ID",on_delete=models.CASCADE,)
    mainName  = models.ForeignKey(MainName, to_field="ID", db_column="ID",on_delete=models.CASCADE,)

    def __str__(self):
        return "{}-{}".format(self.mainName,self.profile)

我的问题:

Profile.objects.all().filter(simmatch__mainname__mainname="My Name")