Python使用Flask-SQLAlchemy连接数据库操作示例

本文实例讲述了Python使用Flask-SQLAlchemy连接数据库操作。分享给大家供大家参考，具体如下：

需要安装flask

pip install flask

安装Mysql-Python (这个是py的mysql驱动，这个在官方没有win的支持，只有第三方才有py2.7的whl)

pip install MySQL_python-1.2.5-cp27-none-win_amd64.whl

注：上述whl文件也可点击此处链接下载到本地安装：https://www.lfd.uci.edu/~gohlke/pythonlibs/

安装 Flask-SQLAlchemy

pipi install Flask-SQLAlchemy

注意，如果出现了编码问题，安装的时候，有可能是终端的编码有问题，我换成了git bash shell就没问题了。
myflask.py

#coding:utf-8
from flask import Flask
#安装 python-mysql 因为没有官方支持win版本，只有网上有whl下载
#pip install flask_sqlalchemy
from flask_sqlalchemy import SQLAlchemy
import config #config.py导入
app = Flask(__name__)
app.config.from_object(config)  #SQLALchemy会自动从配置文件读取那个固定的URI字符串
db=SQLAlchemy(app)
db.create_all()
@app.route('/')
def hello_world():
  return '你好世界'
if(__name__=='__main__'):
  app.run(debug=True) #开启debug模式，这里如果出错会直接有提示

config.py

#coding:utf-8
#dialect+driver://username:password@host:port/database
DIALECT='mysql'
DRIVER='mysqldb'
USERNAME='root'
PASSWORD='root'
HOST='127.0.0.1'
PORT='3306'
DATABASE='flask0'
#这个连接字符串变量名是固定的具体 参考 flask_sqlalchemy 文档 sqlalchemy会自动找到flask配置中的 这个变量
SQLALCHEMY_DATABASE_URI='{}+{}://{}:{}@{}:{}/{}?charset=utf8'.format(DIALECT,DRIVER,USERNAME,PASSWORD,HOST,PORT,DATABASE)

运行看控制台：（有一些无关紧要的警告，可以不管）

D:\Python27\python.exe D:/PythonProjects/learn0/myflask.py
D:\Python27\lib\site-packages\flask_sqlalchemy\__init__.py:794: FSADeprecationWarning: SQLALCHEMY_TRACK_MODIFICATIONS adds significant overhead and will be disabled by default in the future.  Set it to True or False to suppress this warning.
  'SQLALCHEMY_TRACK_MODIFICATIONS adds significant overhead and '
D:\Python27\lib\site-packages\sqlalchemy\engine\default.py:470: Warning: Incorrect string value: '\xD6\xD0\xB9\xFA\xB1\xEA...' for column 'VARIABLE_VALUE' at row 478
  cursor.execute(statement, parameters)
 * Restarting with stat
D:\Python27\lib\site-packages\flask_sqlalchemy\__init__.py:794: FSADeprecationWarning: SQLALCHEMY_TRACK_MODIFICATIONS adds significant overhead and will be disabled by default in the future.  Set it to True or False to suppress this warning.
  'SQLALCHEMY_TRACK_MODIFICATIONS adds significant overhead and '
D:\Python27\lib\site-packages\sqlalchemy\engine\default.py:470: Warning: Incorrect string value: '\xD6\xD0\xB9\xFA\xB1\xEA...' for column 'VARIABLE_VALUE' at row 478
  cursor.execute(statement, parameters)
 * Debugger is active!
 * Debugger PIN: 164-312-281
 * Running on http://127.0.0.1:5000/ (Press CTRL+C to quit)
127.0.0.1 - - [18/Oct/2017 16:01:03] "GET / HTTP/1.1" 200 -
127.0.0.1 - - [18/Oct/2017 16:01:04] "GET / HTTP/1.1" 200 -
127.0.0.1 - - [18/Oct/2017 16:01:06] "GET / HTTP/1.1" 200 -

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