初学flask_sqlalchemy

#coding=UTF8
#!/usr/bin/env python
from flask import Flask
from flask_sqlalchemy import SQLAlchemy

app=Flask(__name__)
app.config['SQLALCHEMY_DATABASE_URI'] = 'mysql://qhz:qhz123@10.10.10.57:3560/study'
app.config['SECRET_KEY'] = 'SQLalPython'
db = SQLAlchemy(app)

class User(db.Model):
    __tablename__ = 'BlogUser'
    id=db.Column(db.Integer,primary_key=True)
    username=db.Column(db.String(50),unique=True)
    password=db.Column(db.String(100))
    email=db.Column(db.String(100),unique=True)
    
    def __init__(self,username,password,email):
        self.username = username
        self.password = password
        self.email    = email
    
    def __repr__(self):
        return '<User : %r>' % self.username
    
    
class Admin(db.Model):
    __tablename__ = 'BlogAdmin'
    id=db.Column(db.Integer,primary_key=True)
    username=db.Column(db.String(50),unique=True)
    password=db.Column(db.String(100))
    email=db.Column(db.String(100),unique=True)
    
    def __init__(self,username,password,email):
        self.username = username
        self.password = password
        self.email    = email
        
    def __repr__(self):
        return '<User : %r>' % self.username
    
db.create_all()
a=User(username='jack',password='jack123',email='world1@163.com')
b=User(username='mike',password='mike123',email='world7@163.com')
c=Admin(username='qhz',password='qhz1123',email='world2@163.com')
try:
    db.session.add(a)
    db.session.add(b)
    db.session.add(c)

    db.session.commit()
except StandardError,e:
    db.session.rollback()
    print e

     运行以后到数据库看时，已经自动生成了2个表，表里也已经有内容数据了。python