Flask数据库集成的介绍

from flask import Flask

from flask_sqlalchemy import SQLAlchemy

app = Flask(__name__)

basedir = os.path.abspath(app.root_path)

app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///' + os.path.join(basedir, 'data.db')

app.config['SQLALCHEMY_TRACK_MODIFICATioNS'] = False

db = SQLAlchemy(app)

from app import db

class User(db.Model):

    id = db.Column(db.Integer, primary_key=True)

    user_name = db.Column(db.String)

    passWord = db.Column(db.String)

>>> from app import db  # 从app.py中导入db实例

>>> from model import *  # 从model.py中导入所有模型类

>>> db.create_all()  # 用db.create_all()创建数据库表 

>>> from app import db  # 从app.py中导入db实例

>>> from model import User   # 导入模型类User

>>> user1=User(user_name='tigeriaf', password='123456')  # 创建用户1

>>> user2=User(user_name='admin', password='123456')  # 创建用户2

# 添加新创建的对象到数据库会话中

>>> db.session.add(user1)

>>> db.session.add(user2)

# 将数据库会话提交，数据写入data.db文件

>>> db.session.commit()

# 测试

>>> print(user1.id)

1

>>> print(user2.id)

2

# 查询全部

>>> User.query.all()

[<User 1>, <User 2>]

# 查询指定id的记录

>>> user1=User.query.get(1)

>>> user1.user_name

'tigeriaf'

# 查询条数

>>> User.query.count()

2

# 查询user_name为admin的用户

>>> User.query.filter_by(user_name='admin').all()

[<User 2>]

>>> user2=User.query.get(2)

>>> user2.user_name

'admin'

>>> user2.user_name='张三'

>>> db.session.commit()

>>> user2.user_name

'张三'

>>> db.session.delete(user2)

>>> db.session.commit()

>>> user2=User.query.get(2)

>>> print(user2)

None

@app.route('/user', methods=['GET', 'POST'])

def user():

    if request.method == 'POST':

        user_name = request.fORM['user_name']

        password = request.form['password']

        user = User(user_name=user_name, password=password)

        db.session.add(user)

        db.session.commit()

        return 'user:{} add success! id:{}'.format(user_name, user.id)

    else:

        user_id = request.args.get('user_id')

        user = User.query.get(user_id)

        if user:

            return 'Hello user:{}!'.format(user.user_name)

        else:

            return 'failed'