Django - Python 3 - "AssertionError:一个模型不能有多个AutoField."

Question

我对此感到疯狂.

我用MySQLWorkbench创建了我的数据库

这是我的架构

比我使用terminal命令获取模型代码:

$python3 manage.py inspectie

在将代码传递给我的models.py之后,我尝试使用shell中的模型

$ python3 manage.py shell

但后来我总是得到这个错误:

"AssertionError:模型不能有多个AutoField."

但错误没有意义,因为每个模型中只有一个AutoField,请参阅:

class Brands(models.Model):
    bid = models.AutoField(db_column='BID')  # Field name made lowercase.
    name = models.CharField(db_column='Name', max_length=45, blank=True, null=True)  # Field name made lowercase.
    fair = models.IntegerField(db_column='Fair', blank=True, null=True)  # Field name made lowercase.
    eco = models.IntegerField(db_column='Eco', blank=True, null=True)  # Field name made lowercase.
    country = models.CharField(db_column='Country', max_length=45, blank=True, null=True)  # Field name made lowercase.
    companies = models.ForeignKey('Companies', models.DO_NOTHING, db_column='Companies_ID')  # Field name made lowercase.

    class Meta:
        managed = False
        db_table = 'Brands'
        unique_together = (('bid', 'companies'),)


class Companies(models.Model):
    cid = models.AutoField(db_column='CID')  # Field name made lowercase.
    name = models.CharField(db_column='Name', max_length=45, blank=True, null=True)  # Field name made lowercase.
    fair = models.IntegerField(db_column='Fair', blank=True, null=True)  # Field name made lowercase.
    eco = models.IntegerField(db_column='Eco', blank=True, null=True)  # Field name made lowercase.
    country = models.CharField(db_column='Country', max_length=45, blank=True, null=True)  # Field name made lowercase.
    concerns = models.ForeignKey('Concerns', models.DO_NOTHING, db_column='Concerns_ID')  # Field name made lowercase.

    class Meta:
        managed = False
        db_table = 'Companies'
        unique_together = (('cid', 'concerns'),)


class Concerns(models.Model):
    cid = models.AutoField(db_column='CID', primary_key=True)  # Field name made lowercase.
    name = models.CharField(db_column='Name', max_length=45, blank=True, null=True)  # Field name made lowercase.
    fair = models.IntegerField(blank=True, null=True)
    eco = models.IntegerField(db_column='Eco', blank=True, null=True)  # Field name made lowercase.
    country = models.CharField(db_column='Country', max_length=45, blank=True, null=True)  # Field name made lowercase.

    class Meta:
        managed = False
        db_table = 'Concerns'


class Products(models.Model):
    pid = models.AutoField(db_column='PID')  # Field name made lowercase.
    name = models.CharField(db_column='Name', max_length=45, blank=True, null=True)  # Field name made lowercase.
    ean = models.IntegerField(db_column='EAN', blank=True, null=True)  # Field name made lowercase.
    fair = models.IntegerField(db_column='Fair', blank=True, null=True)  # Field name made lowercase.
    eco = models.IntegerField(db_column='Eco', blank=True, null=True)  # Field name made lowercase.
    companies_id = models.IntegerField(db_column='Companies_ID')  # Field name made lowercase.
    brands = models.ForeignKey(Brands, models.DO_NOTHING, db_column='Brands_ID')  # Field name made lowercase.
    brands_companies = models.ForeignKey(Brands, models.DO_NOTHING, db_column='Brands_Companies_ID')  # Field name made lowercase.

    class Meta:
        managed = False
        db_table = 'Products'
        unique_together = (('pid', 'companies_id', 'brands', 'brands_companies'),)


class ProductsHasShoppinglists(models.Model):
    products = models.ForeignKey(Products, models.DO_NOTHING, db_column='Products_ID')  # Field name made lowercase.
    products_companies = models.ForeignKey(Products, models.DO_NOTHING, db_column='Products_Companies_ID')  # Field name made lowercase.
    shoppinglists = models.ForeignKey('Shoppinglists', models.DO_NOTHING, db_column='ShoppingLists_ID')  # Field name made lowercase.
    shoppinglists_users = models.ForeignKey('Shoppinglists', models.DO_NOTHING, db_column='ShoppingLists_Users_ID')  # Field name made lowercase.

    class Meta:
        managed = False
        db_table = 'Products_has_ShoppingLists'
        unique_together = (('products', 'products_companies', 'shoppinglists', 'shoppinglists_users'),)


class Shoppinglists(models.Model):
    id = models.AutoField(db_column='ID')  # Field name made lowercase.
    products = models.CharField(db_column='Products', max_length=45, blank=True, null=True)  # Field name made lowercase.
    users = models.ForeignKey('Users', models.DO_NOTHING, db_column='Users_ID')  # Field name made lowercase.

    class Meta:
        managed = False
        db_table = 'ShoppingLists'
        unique_together = (('id', 'users'),)


class Users(models.Model):
    uid = models.AutoField(db_column='UID', primary_key=True)  # Field name made lowercase.
    firstname = models.CharField(db_column='FirstName', max_length=45, blank=True, null=True)  # Field name made lowercase.
    lastname = models.CharField(db_column='LastName', max_length=45, blank=True, null=True)  # Field name made lowercase.
    email = models.CharField(db_column='Email', max_length=45, blank=True, null=True)  # Field name made lowercase.

    class Meta:
        managed = False
        db_table = 'Users'

我只是不明白这个问题!

Answer 1

来自docs:

默认情况下,Django为每个模型提供以下字段:

id = models.AutoField(primary_key = True)

这是一个自动递增的主键.

如果您要指定自定义主键,只需在其中一个字段上指定primary_key = True即可.如果Django看到你明确设置了Field.primary_key,它将不会添加自动id列.

每个模型只需要一个字段即可使primary_key = True(显式声明或自动添加).

所以尝试设置primary_key=True如下:

bid = models.AutoField(db_column='BID', primary_key=True)