pip3 install flask_sqlalchemy
2.连接数据库
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()
