app= Flask(__name__)#载入数据库配置app.config.from_object(Config)#创建sqlalchemy工具对象db =SQLAlchemy(app)classUser(db.Model):__tablename__='user'id= db.Column(db.Integer, primary_key=True) username= db.Column(db.String(32), unique =True) email= db.Column(db.String(255), unique ...
(常用) info_id = db.Column(db.Integer, db.ForeignKey('user_info.id', ondelete='SET NULL')) #--- user_obj = User.query.filter(User.id == 1).first() info = UserInfo.query.filter(UserInfo.id == user_obj.info_id).first() db.session.delete(info) db.session.commit() 一对多 创建...
db=SQLAlchemy(app)classRole(db.Model):"""角色"""__tablename__='roles'#定义列对象id = db.Column(db.Integer, primary_key=True) name= db.Column(db.String(64), unique=True)#设置关系在一的一方设置relationship, backref用于关联表的方向查询使用us = db.relationship('User', backref='role', ...
db=SQLAlchemy(app) 2. 定义模型 模型是数据库表的 Python 类,每个模型类代表数据库中的一张表。 实例 classUser(db.Model): id=db.Column(db.Integer,primary_key=True) username=db.Column(db.String(80),unique=True,nullable=False) email=db.Column(db.String(120),unique=True,nullable=False) def_...
db = SQLAlchemy(app) class User(db.Model): __tablename__ = 'user' id = db.Column(db.Integer, primary_key=True, autoincrement=True) username = db.Column(db.String(50), nullable=False) password = db.Column(db.String(50), nullable=False) ...
#查询时会显示原始SQL语句 app.config['SQLALCHEMY_ECHO'] = True db = SQLAlchemy(app) class Role(db.Model): # 定义表名 __tablename__ = 'roles' # 定义列对象 id = db.Column(db.Integer, primary_key=True) name = db.Column(db.String(64), unique=True) ...
from flask_sqlalchemy import SQLAlchemy db = SQLAlchemy() class User(db.Model): id = db.Column(db.Integer, nullable=False, autoincrement=True, primary_key=True) username = db.Column(db.String(15), nullable=False) password = db.Column(db.String(128), nullable=False) ...
要从Flask SQLAlchemy数据库中删除或修改表,您需要执行以下步骤: ### 删除表 1. **定义模型类**:首先,确保您已经定义了要删除的表的模型类。 ```python from...
Model): __tablename__ = 'fdog' id = db.Column(db.Integer, primary_key=True, autoincrement=True) # SQLAlchemy 要求 模型中必须有一个主键否则保存 comment = db.Column(db.String(255), default="备注描述说明") fid = db.Column(db.Integer, db.ForeignKey(Dog.id)) # 注意外键的字段不能是...
sqlalchemy.exc.NoForeignKeysError:Couldnotdeterminejoinconditionbetweenparent/childtablesonrelationshipversion_patch.patchcode-therearenoforeignkeyslinkingthesetables.EnsurethatreferencingcolumnsareassociatedwithaForeignKeyorForeignKeyConstraint,orspecifya'primaryjoin'expression. 代码: classtrans_inst(db.Model): __tabl...