Django 错误 : "Unknown column ' categorytree. id' 在 'field list' 中“

Question

通过 Django shell 运行以下命令时:

from myApp.models import *
print Categorytree.objects.all()

我收到此错误消息:

OperationalError: (1054, "Unknown column 'categorytree.id' in 'field list'")

这就是我的模型的样子:

class Categorytree(models.Model):
    level = models.IntegerField(db_column='Level')  # Field name made lowercase.
    categorynode_idcategorynode = models.ForeignKey(Categorynode, models.DO_NOTHING, db_column='CategoryNode_idCategoryNode')  # Field name made lowercase.
    categorynode_idancestorcategorynode = models.ForeignKey(Categorynode, models.DO_NOTHING, db_column='CategoryNode_idAncestorCategoryNode', related_name='+')  # Field name made lowercase.

    class Meta:
        managed = False
        db_table = 'categorytree'
        unique_together = (('categorynode_idcategorynode', 'categorynode_idancestorcategorynode'),)

请注意，它没有主键，也不应该有，但 Django 似乎认为会有一个主键 .id 字段。

Answer 1

引用Django docs :

Each model requires exactly one field to have primary_key=True (either explicitly declared or automatically added).

如果需要访问没有主键的表，则需要使用其他工具，例如SQLAlchemy .