Question

需要帮助... 我有点认为将关系型“帮助器”表定义为类是不好的风格，但想使用它来存储属于该类的信息并方便地访问它我究竟做错了什么？当我将其设置为表格时，我不会遇到任何问题...

谢谢！

from alexa import db


# Relation tables


class Todos(db.Model):
    _tablename_ = 'todos'
    id = db.Column(db.Integer, primary_key=True)
    order_id = db.Column(db.Integer,
                         db.ForeignKey("order.id"))
    sequence = db.Column(db.Integer)
    step_id = db.Column(db.Integer,
                        db.ForeignKey("step.id"))

    orders = db.relationship("Order",
                             backref=db.backref("todos",
                                                cascade="all, delete-orphan"))
    steps = db.relationship("Step",
                            backref=db.backref("todos",
                                               cascade="all, delete-orphan"))

# Actual tables


class Vehicle(db.Model):
    id = db.Column(db.String(20), primary_key=True)
    customer_number = db.Column(db.Integer, unique=True, nullable=False)
    orders = db.relationship("Order", backref="order_vehicle")


class Order(db.Model):
    _tablename_ = 'order'
    id = db.Column(db.Integer, primary_key=True)
    title = db.Column(db.String(200), unique=False, nullable=False)
    status_id = db.Column(db.Integer, db.ForeignKey("status.id"))
    vehicle_id = db.Column(db.Integer, db.ForeignKey("vehicle.id"))


class Step(db.Model):
    _tablename_ = 'step'
    id = db.Column(db.Integer, primary_key=True)
    title = db.Column(db.String(200), unique=False, nullable=False)
    description = db.Column(db.String(200), unique=False, nullable=False)
    status_id = db.Column(db.Integer, db.ForeignKey("status.id"))

    comment_id = db.Column(db.Integer, db.ForeignKey("comment.id"))


class Status(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    title = db.Column(db.String(200), unique=False, nullable=False)
    steps = db.relationship("Step", backref="step")
    orders = db.relationship("Order", backref="order_status")


class Comment(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    text = db.Column(db.String(2000), unique=False, nullable=False)
    step = db.relationship("Step", backref="step_comment")

我的错误：

  File "C:\Anaconda3\lib\site-packages\sqlalchemy\engine\default.py", line 507, in do_execute
    cursor.execute(statement, parameters)
sqlite3.OperationalError: no such table: order

...

    context)
  File "C:\Anaconda3\lib\site-packages\sqlalchemy\engine\default.py", line 507, in do_execute
    cursor.execute(statement, parameters)
sqlalchemy.exc.OperationalError: (sqlite3.OperationalError) no such table: order [SQL: 'SELECT "order".id AS order_id, "order".title AS order_title, "order".status_id AS order_status_id, "order".vehicle_id AS order_vehicle_id \nFROM "order" \nWHERE "order".id = ?\n LIMIT ? OFFSET ?'] [parameters: ('1', 1, 0)] (Background on this error at: http://sqlalche.me/e/e3q8)

Flask-SQLAlchemy类/表多对多关系-找不到表

0 个答案: