Python 在与关联表的多对多关系中插入数据时出错
我有很多这样的数据库Python 在与关联表的多对多关系中插入数据时出错,python,flask,sqlalchemy,many-to-many,Python,Flask,Sqlalchemy,Many To Many,我有很多这样的数据库 association_table = db.Table('association', db.Column('meal_id', db.Integer, db.ForeignKey('meals.id')), db.Column('order_id', db.Integer, db.ForeignKey('orders.id'))
association_table = db.Table('association',
db.Column('meal_id', db.Integer, db.ForeignKey('meals.id')),
db.Column('order_id', db.Integer, db.ForeignKey('orders.id'))
)
class Order(db.Model):
__tablename__ = 'orders'
id = db.Column(db.Integer, primary_key=True)
data = db.Column(db.String)
meals = db.relationship(
"Meals", secondary=association_table, back_populates="orders"
)
class Meals(db.Model):
__tablename__ = 'meals'
id = db.Column(db.Integer, primary_key=True)
title = db.Column(db.String, unique=True)
price = db.Column(db.Float)
orders = db.relationship(
"Order", secondary=association_table, back_populates="meals"
)
我尝试将数据插入表顺序
order_to_database = Order (data='05_03_2021',
meals = 1
)
db.session.add(order_to_database)
db.session.commit()
膳食是膳食的id。我认为这是一个错误:
如何解决此问题?在使用
db时。关系ORM期望fines
应该是fines
的实例,而不是整数
breakfast_meal = Meal(id=1,title='Lunch',price=9)
order_to_database = Order(data='05_03_2021')
order_to_database.meals.append(breakfast_meal)
db.session.add(order_to_database)
db.session.commit()
如果您正在使用数据库中已有的膳食,则可以执行以下操作:
lunch_meal = Meal.query.filter(Meal.id==10).first()
....
order_to_database.meals.append(lunch_meal)
....
db.session.commit()
fines
应该是fines
的实例,而不是整数。我应该如何在表中插入数据?