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flask:用Flask-SQLAlchemy访问mysql

news 2026/1/9 5:47:10

一，安装第三方库

$ pip3 install Flask-SQLAlchemy

二，建立到数据库的连接

import os
from dotenv import load_dotenvfrom flask import Flask,jsonifyfrom flask_sqlalchemy import SQLAlchemy# 加载变量
dotenv_path = os.path.join(os.path.dirname(__file__), '.env')
load_dotenv(dotenv_path=dotenv_path, verbose=True, override=True)
db_uri = os.getenv("SQLALCHEMY_DATABASE_URI")
print("打印配置项:")
print(db_uri)app = Flask(__name__)# 数据库信息
host = '127.0.0.1'
port = '3306'
database = 'mybase'
username = 'root'
password = 'rootpassword'# 数据库类型+连接数据库的插件，这里使用的pymysql
DB_URI = f'mysql+pymysql://{username}:{password}@{host}:{port}/{database}'
# 配置数据库连接
app.config['SQLALCHEMY_DATABASE_URI'] = DB_URI
# 绑定Flask对象
db = SQLAlchemy()
db.init_app(app)from controller.admin import admin
from controller.user import userapp.register_blueprint(admin,url_prefix="/admin")
app.register_blueprint(user,url_prefix="/user")@app.errorhandler(404)
def page_not_found(error):data = {"status": "failed","code": 500,"msg": "错误的路径"}return jsonify(data), 404if __name__ == '__main__':app.run(debug=True)

三，查询数据

model类

from app import db# 设计数据库模型
class User(db.Model):# 指定表名称__tablename__ = 'user'id = db.Column(db.Integer, primary_key=True)username = db.Column(db.String(64), nullable=False)nickname = db.Column(db.String(256), nullable=False)age = db.Column(db.Integer, default=0)city = db.Column(db.String(256), nullable=False)

查询:

from flask import Blueprint,jsonify,render_template,requestfrom models.user import Useruser = Blueprint('user', __name__)@user.route("/list/")
def user_list():meta = {"title": "用户列表","code": 200,"msg": ""}# 得到数据库中的数据users = User.query.all()return render_template('user/list.html', meta=meta, users=users)