3.Flask-SQLAlchemy
(1)安装
pip install flask_sqlalchemy
(2)数据库连接
from flask import Flask # 1.导入 from flask_sqlalchemy import SQLAlchemy app = Flask(__name__) #2.定义要连接的数据库 DB_URI = "mysql+pymysql://root:123456@127.0.0.1:3306/learn_sqlalchemy?charset=utf8" #3.添加到到配置中 app.config['SQLALCHEMY_DATABASE_URI'] = DB_URI
app.config['SQLALCHEMY_TRACK_MODIFICATIONS'] =False # 4.实例化一个对象,将app传进去 db = SQLAlchemy(app) @app.route('/') def hello_world(): return 'Hello World!' if __name__ == '__main__': app.run()
(3)创建表
from flask import Flask from flask_sqlalchemy import SQLAlchemy app = Flask(__name__) DB_URI = "mysql+pymysql://root:123456@127.0.0.1:3306/learn_sqlalchemy?charset=utf8" app.config['SQLALCHEMY_DATABASE_URI'] = DB_URI app.config['SQLALCHEMY_TRACK_MODIFICATIONS'] = False 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) class Article(db.Model): __tablename__ = "article" id = db.Column(db.Integer, primary_key=True, autoincrement=True) title = db.Column(db.String(50), nullable=False) uid = db.Column(db.Integer,db.ForeignKey("user.id")) author = db.relationship("User",backref='article') db.drop_all() #删除表 db.create_all() #创建表 @app.route('/') def hello_world(): return 'Hello World!' if __name__ == '__main__': app.run()
(4)添加数据
from flask import Flask from flask_sqlalchemy import SQLAlchemy app = Flask(__name__) DB_URI = "mysql+pymysql://root:123456@127.0.0.1:3306/learn_sqlalchemy?charset=utf8" app.config['SQLALCHEMY_DATABASE_URI'] = DB_URI app.config['SQLALCHEMY_TRACK_MODIFICATIONS'] = False 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) class Article(db.Model): __tablename__ = "article" id = db.Column(db.Integer, primary_key=True, autoincrement=True) title = db.Column(db.String(50), nullable=False) uid = db.Column(db.Integer,db.ForeignKey("user.id")) author = db.relationship("User",backref='article') # db.drop_all() #删除表 # db.create_all() #创建表 #添加数据 user = User(username='derek') article = Article(title='今天5/27号') article.author = user db.session.add(article) db.session.commit() @app.route('/') def hello_world(): return 'Hello World!' if __name__ == '__main__': app.run()
(5)查看、修改和删除
from flask import Flask from flask_sqlalchemy import SQLAlchemy app = Flask(__name__) DB_URI = "mysql+pymysql://root:123456@127.0.0.1:3306/learn_sqlalchemy?charset=utf8" app.config['SQLALCHEMY_DATABASE_URI'] = DB_URI app.config['SQLALCHEMY_TRACK_MODIFICATIONS'] = False 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) def __repr__(self): return "<username:%s>"%self.username class Article(db.Model): __tablename__ = "article" id = db.Column(db.Integer, primary_key=True, autoincrement=True) title = db.Column(db.String(50), nullable=False) uid = db.Column(db.Integer,db.ForeignKey("user.id")) author = db.relationship("User",backref='article') # db.drop_all() #删除表 # db.create_all() #创建表 # 1.添加数据 # user = User(username='derek') # article = Article(title='今天5/27号') # article.author = user # # db.session.add(article) # db.session.commit() # 2.查询数据 # users=User.query.all() # print(users) # 3.修改数据,先查找出来再修改 # user = User.query.filter(User.username=='derek').first() # user.username = 'jack' # db.session.commit() # 4.删除数据 user = User.query.filter(User.username=='jack').first() db.session.delete(user) db.session.commit() @app.route('/') def hello_world(): return 'Hello World!' if __name__ == '__main__': app.run()
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