Flask-SQLAlchemy的使用

初始化和设置数据库配置信息

1、使用flask_sqlalchemy中SQLAlchemy进行初始化

from flask_sqlalchemy import  SQLAlchemy
app = Flask(__name__)
db = SQLAlchemy(app)

2、配置数据库config

DIALECT = 'mysql'
DRIVER = 'mysqldb'
USERNAME = 'root'
PASSWORD = 'mysql'
HOST = '127.0.0.1'
PORT = '3306'
DATABASE = 'flask_sql'
SQLALCHEMY_DATABASE_URI = "{}+{}://{}:{}@{}:{}/{}?charset=utf8".format(DIALECT,DRIVER,USERNAME,PASSWORD,HOST,PORT,DATABASE)
SQLALCHEMY_TRACK_MODIFICATIONS = False

创建数据库 注：数据库可以提前创建好

create database flask_demo charset utf8;

3、在主app文件中添加配置

app = Flask(__name__)
app.config.from_object(config)
db = SQLAlchemy(app)

4、测试数据库是否连接成功 注:运行程序没有报错表示连接成功

db.create_all()

• 5、使用Flask-SQLAlchemy 创建模型与表的映射

class Articles(db.Model):
    __tablename__ = 'articles'
    id = db.Column(db.Integer,primary_key=True,autoincrement=True)
    # nullable=False 不能为空
    title = db.Column(db.String(32),nullable=False)
    content = db.Column(db.Text,nullable=False)
db.drop_all()

• 创建数据库表完整代码

from flask import Flask
import config
from flask_sqlalchemy import  SQLAlchemy

app = Flask(__name__)
app.config.from_object(config)
db = SQLAlchemy(app)

class Article(db.Model):
    __tablename__ = 'article'
    id = db.Column(db.Integer,primary_key=True,autoincrement=True)
    # nullable=False 不能为空
    title = db.Column(db.String(32),nullable=False)
    content = db.Column(db.Text,nullable=False)


class Articles(db.Model):
    __tablename__ = 'articles'
    id = db.Column(db.Integer,primary_key=True,autoincrement=True)
    # nullable=False 不能为空
    title = db.Column(db.String(32),nullable=False)
    content = db.Column(db.Text,nullable=False)
db.drop_all()
db.create_all()


@app.route('/')
def index():
    return 'Hello World'


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