1、安装 flask_sqlalchemy 和 Flask

注意：如果没有安装 conda 请查看 Anaconda安装教程 

conda install PyMySQL
conda install flask_sqlalchemy
conda install Flask

如果安装flask-sqlalchemy失败，请查看一下文档

conda安装错误处理

 conda install -c conda-forge flask-sqlalchemy

2、创建配置文件 config.py

HOST = "127.0.0.1"
PORT = "3306"
DB = "smart_medicine"
USER = "root"
PASS = ""
CHARSET = "utf8"
DB_URI = "mysql+pymysql://{}:{}@{}:{}/{}?charset={}".format(USER, PASS, HOST, PORT, DB, CHARSET)
SQLALCHEMY_DATABASE_URI = DB_URI

3、编写数据库映射对象，并进行CURD操作

from flask_sqlalchemy import SQLAlchemy
from datetime import datetime
from flask import Flask
import config
app = Flask(__name__)
app.config.from_object(config)
#  设置每次请求结束后会自动提交数据库中的改动
app.config['SQLALCHEMY_COMMIT_ON_TEARDOWN'] = True
# 打印 SQL语句
app.config['SQLALCHEMY_ECHO'] = True
db = SQLAlchemy(app)

# 创建 User 对象
class Users(db.Model):
    __tablename__ = 'users_info'
    id = db.Column(db.Integer, primary_key=True, autoincrement=True)
    username = db.Column(db.String(32), nullable=False)
    password = db.Column(db.String(100), nullable=False)
    email = db.Column(db.String(100), nullable=False)
    register_time = db.Column(db.DateTime, nullable=False, default=datetime.now())
# 创建表
# db.create_all()

# 插入数据
us1 = Users(username='wang', email='wang@163.com', password='123456')
db.session.add(us1)

# 查询数据
user = Users.query.filter(Users.username == 'wang').first()
print(user)

# 修改
wang = Users.query.filter(Users.username == 'wang').first()
wang.email = "email@qq.com"
db.session.commit()
wang = Users.query.filter(Users.username == 'wang').first()
print(wang)

# 删除
# result = Users.query.filter(Users.username == 'wang').first()
# db.session.delete(result)

# 查询10条记录
users = Users.query.limit(10).all()
print(users)
# 查询所以数据
result = Users.query.all()
print(user)

4、更多细节碎片的知识

http://www.pythondoc.com/flask-sqlalchemy/queries.html