class Post(db.Model):
"""Represents Proected posts."""
__tablename__ = 'posts'
id = db.Column(db.String(45), primary_key=True)
title = db.Column(db.String(255))
text = db.Column(db.Text())
publish_date = db.Column(db.DateTime)
# Set the foreign key for Post
user_id = db.Column(db.String(45), db.ForeignKey('users.id'))
comments = db.relationship('Comment', backref='posts', lazy='dynamic')
# many to many: posts <==> tags
tags = db.relationship(
'Tag',
#会告知 SQLAlchemy 该 many to many 的关联保存在 posts_tags 表中
secondary=posts_tags,
#声明表之间的关系是双向，帮助手册 help(db.backref)。
# 需要注意的是：在 one to many 中的 backref 是一个普通的对象，
# 而在 many to many 中的 backref 是一个 List 对象
backref=db.backref('posts', lazy='dynamic'))
def __init__(self, title):
self.title = title
def __repr__(self):
return "<Model Post `{}`>".format(self.title)
class ItemModel(db.Model):
__tablename__ = 'items'
id_ = db.Column(db.Integer, primary_key=True)
name = db.Column(db.String(20))
price = db.Column(db.Float(precision=2))
store_id = db.Column(db.Integer, db.ForeignKey('stores.id_'))
store = db.relationship('StoreModel')
def __init__(self, name, price, store_id):
self.name = name
self.price = price
self.store_id = store_id
def json(self):
return {
'name': self.name,
'price': self.price,
'store_id': self.store_id
}
@classmethod
def get_by_name(cls, name):
return cls.query.filter_by(name=name).first()
def save_to_db(self):
db.session.add(self)
db.session.commit()
def delete_from_db(self):
db.session.delete(self)
db.session.commit()
class StoreModel(db.Model):
__tablename__ = 'stores'
id_ = db.Column(db.Integer, primary_key=True)
name = db.Column(db.String(20))
# back reference
items = db.relationship('ItemModel', lazy = 'dynamic')
def __init__(self,name):
self.name = name
def json(self):
return {'name':self.name, 'items':[x.json() for x in self.items.all()]}
@classmethod
def get_by_name(cls,name):
return cls.query.filter_by(name=name).first()
def save_to_db(self):
db.session.add(self)
db.session.commit()
def delete_from_db(self):
db.session.delete(self)
db.session.commit()
class User(db.Model, UserMixin):
"""
Saving new users data into our database
"""
id = db.Column(db.Integer, primary_key=True)
username = db.Column(db.String(20), unique=True, nullable=False)
firstname = db.Column(db.String(20), nullable=False)
lastname = db.Column(db.String(20), nullable=False)
email = db.Column(db.String(120), unique=True, nullable=False)
password = db.Column(db.String(60), nullable=False)
garments = db.relationship('Garment', backref='seller', lazy=True)
messages = db.relationship('Message', backref='sender', lazy=True)
def __repr__(self):
return f"User('{self.username}', '{self.email}')"
def set_password(self, secret):
self.password = generate_password_hash(secret)
def check_password(self, secret):
return check_password_hash(self.password, secret)
class User(db.Model):
__tablename__ = 'users'
id = db.Column(db.String(45), primary_key=True)
username = db.Column(db.String(255))
password = db.Column(db.String(255))
#会在 SQLAlchemy 中创建一个虚拟的列，该列会与 Post.user_id (db.ForeignKey) 建立联系。这一切都交由 SQLAlchemy 自身管理
posts = db.relationship(
'Post',
#用于指定表之间的双向关系，如果在一对多的关系中建立双向的关系，这样的话在对方看来这就是一个多对一的关系
backref='users',
#指定 SQLAlchemy 加载关联对象的方式，lazy=subquery: 会在加载 Post 对象后，将与 Post 相关联的对象全部加载
lazy='dynamic')
def __init__(self, id, username, password):
self.id = id
self.username = username
self.password = password
def __repr__(self):
return '<Model User `{}`>'.format(self.username)