sqlalchemy.exc.IntegrityError：（sqlite3.IntegrityError）os_info.id可能不为NULL

Question

我有一个sqlalchemy表对象并尝试插入一些值，但它会引发错误，如

sqlalchemy.exc.IntegrityError: (sqlite3.IntegrityError) os_info.id may not be NULL'

我无法理解这是怎么发生的，因为我使用id

指定了列autoincrement=True

class Os(Base):
    __tablename__ = 'os_info'

    id = Column(Integer, autoincrement=True, primary_key=True)
    hostname = Column(String(32), nullable=False)
    dist = Column(String(32), nullable=False)
    instruct_set = Column(String(32), nullable=False)

    def __repr__(self):
        return "<Os(hostname='%s',dist='%s',instruct_set='%s')>" % (self.hostname, self.dist, self.instruct_set)