python的flask框架连接mysql数据库

《flaskweb》开发里用的数据库是sqlite ，我们常用的是mysql等数据库，下面介绍下如何在flask下连接mysql。

1. 驱动准备。

pip install flask-sqlalchemy
pip install mysql-python
主要是这两个驱动。安装方法还有比较多，就不过多叙述了。

1. 数据库设置

首先导包
from flask_sqlalchemy import SQLAlchemy
然后配置数据库

app.config['SQLALCHEMY_DATABASE_URI']='mysql://root:123@localhost:3306/test' 
#这里登陆的是root用户，要填上自己的密码，MySQL的默认端口是3306，填上之前创建的数据库名test
app.config['SQLALCHEMY_TRACK_MODIFICATIONS']=True 
#设置这一项是每次请求结束后都会自动提交数据库中的变动

1. 定义模型，建立关系：hello.py 中

class Role(db.Model):
    __tablename__ = 'roles'
    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.String(64), unique=True)
    users = db.relationship('User', backref='role', lazy='dynamic')

    def __repr__(self):
        return '<Role %r>' % self.name


class User(db.Model):
    __tablename__ = 'users'
    id = db.Column(db.Integer, primary_key=True)
    username = db.Column(db.String(64), unique=True, index=True)
    role_id = db.Column(db.Integer, db.ForeignKey('roles.id'))

    def __repr__(self):
        return '<User %r>' % self.username

1. 运行hello.py
   运行hello.py,在控制台可以创建数据库，添加数据等操作了。
   完整hello.py代码

# -*- coding: utf-8 -*-
_author_ = 'Pylar'
from flask import Flask,render_template,session,redirect,url_for,flash
from flask_script import Manager
from flask_bootstrap import Bootstrap
from datetime import datetime
from flask_moment import Moment
from flask_wtf import Form
from wtforms import StringField,SubmitField
from wtforms.validators import Required
from flask_sqlalchemy import SQLAlchemy

app = Flask(__name__)
app.config['SECRET_KEY'] = 'haha'
app.config['SQLALCHEMY_DATABASE_URI']='mysql://root:123@localhost:3306/test' #这里登陆的是root用户，要填上自己的密码，MySQL的默认端口是3306，填上之前创建的数据库名text1
app.config['SQLALCHEMY_TRACK_MODIFICATIONS']=True #设置这一项是每次请求结束后都会自动提交数据库中的变动


bootstrap = Bootstrap(app)
moment = Moment(app)
db = SQLAlchemy(app) #实例化
# manager = Manager(app)

class Role(db.Model):
    __tablename__ = 'roles'
    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.String(64), unique=True)
    users = db.relationship('User', backref='role', lazy='dynamic')

    def __repr__(self):
        return '<Role %r>' % self.name


class User(db.Model):
    __tablename__ = 'users'
    id = db.Column(db.Integer, primary_key=True)
    username = db.Column(db.String(64), unique=True, index=True)
    role_id = db.Column(db.Integer, db.ForeignKey('roles.id'))

    def __repr__(self):
        return '<User %r>' % self.username



class NameForm(Form):
    name = StringField('What is your name?',validators=[Required()])
    submit = SubmitField('Submit')

@app.errorhandler(404)
def page_not_found(e):
    render_template('404.html'),404

@app.errorhandler(500)
def internal_server_error(e):
    render_template('500.html'),500

@app.route('/',methods = ['GET','POST'])
def index():
    name = None
    form = NameForm()
    if form.validate_on_submit():
        old_name = session.get('name')
        if old_name is not None and old_name != form.name.data:
            flash('Looks like you have changed your name!')
        session['name'] = form.name.data
        return redirect(url_for('index'))
    return render_template('index.html',form=form,name=session.get('name'))

@app.route('/user/<name>')
def user(name):
    return render_template('user.html',name=name)


if __name__ == '__main__':
   app.run(debug=True)

1. 成功