增加：
user =
db.session.add(user)
db.session.commit()
查询：
User.query.filter(User.username == 'mis1114').first()
修改：
user.password = '111111'
db.session.commit()
删除：
db.session.delete(user)
db.session.commit()
from flask import Flask, render_template
from flask_sqlalchemy import SQLAlchemy
import config
app = Flask(__name__)
app.config.from_object(config)
db = SQLAlchemy(app)
class User(db.Model):
__tablename__ = 'user'
id = db.Column(db.Integer, primary_key=True, autoincrement=True)
username = db.Column(db.String(20), nullable=False)
password = db.Column(db.String(20), nullable=False)
nickname = db.Column(db.String(20))
#db.create_all()
#增加
user = User(username ='ll1234',password ='1234',againpass='1234')
db.session.add(user)
db.session.commit()
#查找
# user = User.query.filter(User.username =='ll1234').first()
# user.password ='1234'
# user.againpass='1234'
# print(user.id,user.username,user.password)
#修改
user =User.query.filter(User.username =='aa990').first()
user.password='22365'
print(user.username,user.password)
db.session.commit()
#删除
#user = User.query.filter(User.username =='ll1234').first()
#db.session.delete(user)
#db.session.commit()
@app.route('/')
def hello_world():
return 'Hello World!'
if __name__ == '__main__':
app.run()
