Django的外键（多对多）字段不添加到数据库表

Question

class Organization(models.Model): 
    mLeader = models.ForeignKey(User) 
    mName = models.CharField(max_length=30, default='-') 
    mTel = models.CharField(max_length=15, default='-') 
    mAddress = models.TextField(default='-') 
    mType = models.CharField(max_length=1, default='A') # A : Daycare Center, B : private educational institute, C : Church, D : ... 
    owner = models.ForeignKey('auth.User', related_name='Organization') 

    def __str__(self) : 
     return self.mName 

class OrganizationLeader(models.Model): 
    #private info 
    mUser = models.ForeignKey(User) 
    owner = models.ForeignKey('auth.User', related_name='Leader') 
    # mName = models.CharField(max_length=30, default='-') 

class BusLine(models.Model): 
    mOrganization = models.ForeignKey(Organization) 
    mName = models.CharField(max_length=30, default='-') 
    mIsPrivate = models.BooleanField(default=True) 
    mCreated = models.DateTimeField(auto_now_add=True) 
    mIsCycle = models.BooleanField(default=False) 

    owner = models.ForeignKey('auth.User', related_name='lines') 

    class Meta: 
     ordering = ('mCreated',) 

class BusStation(models.Model): 
    mName = models.CharField(max_length=30, default='-') 
    mCreated = models.DateTimeField(auto_now_add=True) 
    mOrder = models.IntegerField(default=None) 
    mIsStart = models.BooleanField(default=False) 
    mIsEnd = models.BooleanField(default=False) 
    mBusLine = models.ManyToManyField('BusLine', blank=True, null=True) 

    #변수명이 고정돼있어 접미사 붙이지 않음 
    mpoint = models.PointField(default=None) 
    objects = models.GeoManager() 
    Latitude = models.DecimalField(default=0.0, max_digits=10, decimal_places=6) 
    Longitude = models.DecimalField(default=0.0, max_digits=10, decimal_places=6) 

    owner = models.ForeignKey('auth.User', related_name='stations') 

    class Meta: 
     ordering = ['mOrder'] 

class Bus(models.Model): 
    mDriver = models.ForeignKey(User) 
    mDriving = models.BooleanField(default=False) 
    mCurrentStation = models.IntegerField(default=0) 
    mCreated = models.DateTimeField(auto_now_add=True) 
    mName = models.CharField(max_length=100) 
    mBusLine = models.ForeignKey('BusLine', on_delete=models.CASCADE, blank=True, null=True) 
    mArrive = models.BooleanField(default=False) 

    #LSB Data 
    #변수명이 고정돼있어 접미사 붙이지 않음 
    mpoint = models.PointField(default=None) 
    objects = models.GeoManager() 
    Latitude = models.DecimalField(default=0.0, max_digits=10, decimal_places=6) 
    Longitude = models.DecimalField(default=0.0, max_digits=10, decimal_places=6) 

    owner = models.ForeignKey('auth.User', related_name='buses') 

    def save(self, *args, **kwargs): 
     self.Latitude = self.mpoint.y 
     self.Longitude = self.mpoint.x 
     super(Bus, self).save(*args, **kwargs) 

    class Meta: 
     ordering = ('mCreated',) 

class PassengerLogManager(models.Manager): 
    def create_log(self, id): 
     log = self.create(mBusId = id) 
     return log 

class PassengerLog(models.Model): 
    mBusId = models.IntegerField() 
    mCreated = models.DateTimeField(auto_now_add=True,) 
    #JSON 필드에 버스의 한 회차 정류장당 탑승자 리스트가 저장됨 
    mLog = JSONField() 
    objects = PassengerLogManager() 

class AppUser(models.Model): 
    #private info 
    mUser = models.ForeignKey(User) 
    mBaseDestination = models.ForeignKey(
     BusStation, 
     verbose_name = 'BaseDestination', 
     default = '-', 
    ) 
    mName = models.CharField(
     verbose_name = 'UserName', 
     max_length=30, 
     blank = False, 
     default = '-' 
    ) 

    mChild = models.ManyToManyField(
     'self', 
     through = 'ParentToChildEntry', 
     verbose_name = 'Child', 
     through_fields = ('mParent','mChild'), 
     symmetrical = False, 
    ) 
    owner = models.ForeignKey('auth.User', related_name='User') 
    def __str__(self) : 
     return self.mName 

class ParentToChildEntry(models.Model) : 
    mName = models.CharField(
     max_length = 20, 
     verbose_name = 'Title', 
     blank = False, 
     default = '-' 
    ) 
    mParent = models.ForeignKey(
     AppUser, 
     verbose_name = 'Parent', 
     related_name = 'Parent', 
    ) 

    mChild = models.ManyToManyField(
     AppUser, 
     verbose_name = 'Child', 
     related_name = 'Child', 
    ) 
    def __str__(self) : 
     return self.mName 

class OrganizationToUserEntry(models.Model) : 
    mName = models.CharField(
     max_length = 20, 
     verbose_name = 'Title', 
     blank = False, 
     default ='-' 
    ) 
    mOrganizations = models.ForeignKey(
     Organization, 
     verbose_name = 'Organization' 
    ) 
    mUsers = models.ManyToManyField(
     AppUser, 
     verbose_name = 'Users' 
    ) 
    def __str__(self) : 
     return self.mName 

以上是公交管理系统模型。（Django的版本1.11.4） 首先，当我试图启动和管理测试此代码，

错误（1054 “未知列 'DataMng_appuser.mBaseDestination_id' 在 '字段列表'”）

引起，所以我冲DB和迁移模式。
然而，当我试图迁移该模型，系统返回我

[警告：DataMng.BusStation.mBusLine：（fields.W340）空对ManyToManyField没有影响]

我一再发现如何解决这个问题，但我找不到。 请告诉我应该做什么T_T。谢谢你的阅读。

Answer 1

，你可以直接删除选项null=True在mBusLine

class BusStation(models.Model): 
    # other fields 
    mBusLine = models.ManyToManyField('BusLine', blank=True, null=True) 
    #              ^^^^^^^^^^