Flask 项目创建，增删改查：

创建一个空文件pycharm打开，并创建虚拟环境

一次性安装以下所有：pip install -r r.txt

Flask==1.1.4
Flask-Caching==1.10.1
Flask-Cors==3.0.10
Flask-Migrate==2.7.0
Flask-RESTful==0.3.9
Flask-Script==2.0.6
Flask-SQLAlchemy==2.5.1
MarkupSafe==2.0.1
PyJWT==2.3.0
PyMySQL==1.0.2
qiniu==7.6.0
redis==4.2.2

# 可以放置在**.txt文件 一次性安装

挂载项   create_app.py

from flask import Flask
from flask_cors import CORS
from model.model import db
from views.views import goods_dp

def create_app(config):
    flask_app = Flask(__name__)
    
    flask_app.config.from_object(config)    # 挂在配置项

    cors = CORS(flask_app)    # 跨域
    
    flask_app.register_blueprint(goods_dp)    # 注册蓝图
    
    db.init_app(flask_app)    # 绑定数据库连接对象

    # # flask_app.config['SQLALCHEMY_TRACK_MODIFICATIONS'] = True

    return flask_app

程序入口        app.py 

from config.settings import Config
from create_app import create_app

app = create_app(Config)

# if __name__ == '__main__':
#     app.run('127.0.0.1',port=18888)

配置项   config >> settings.py

 current_app.config.get('SECRET_KEY')        # 配置项取值语法

class Config():
    SECRET_KEY = 'dasezytxrdtf'

    SQLALCHEMY_DATABASE_URI = 'mysql+pymysql://root:123456@127.0.0.1:3306/20220919db'

    SQLALCHEMY_TRACK_MODIFICATIONS = False    # 是否追踪数据库发生的变化

    SQLALCHEMY_ECHO = True    # 是否在控制台打印输出sql语句

    JSON_AS_ASCII = False    # 返回JSON的时候不转义中文

 迁移项        manage.py

from flask_migrate import Migrate, MigrateCommand
from flask_script import Manager  # script第三方扩展
from app import app
from model.model import db

# 1.创建命令行对象
manage = Manager(app)

# 2.创建迁移对象
migrate = Migrate(app, db)

# 3.添加迁移命令到命令行对象
manage.add_command('db', MigrateCommand)

# 4.运行
if __name__ == '__main__':
    manage.run()

 模型类        models >> model.py

from flask_sqlalchemy import SQLAlchemy

db = SQLAlchemy()


class GoodsModel(db.Model):
    id = db.Column(db.Integer, primary_key=True, autoincrement=True)
    title = db.Column(db.String(128), comment='商品名')
    desc = db.Column(db.Text, comment='商品简介')
    price = db.Column(db.DECIMAL(10, 2), comment='价格')
    img = db.Column(db.String(128), comment='图片')

创建数据库 settings.py中指定的 20220919db库名

python manage.py db init        # 初始化

python manage.py db migrate        # 迁移数据库

python manage.py db        # 查看所有命令

python manage.py db upgrade        # 执行迁移

  视图        views >> views.py

import random
from datetime import datetime

from flask import Blueprint, request, jsonify
from flask_restful import Api, Resource

from model.model import GoodsModel, db

goods_dp = Blueprint('goods_dp', __name__, url_prefix='/v1')

api = Api(goods_dp)


class GoodsView(Resource):
    def get(self):
        # 查看所有商品
        goods_list = GoodsModel.query.all()     # 获取所有对象
        
        goods_all = []
        for goods in goods_list:
            d = {
                'id': goods.id,
                'title': goods.title,
                'price': str(goods.price),  # DECIMAL类型 不能被JSON序列化
                'desc': goods.desc,
                # 'img': request.scheme + '://' + request.host + '/' + goods.img,
                #   协议 + :// + 主机地址 + / + 图片名
                # 'img': '%s://%s/%s' % (request.scheme, request.host, goods.img)
                'img': 'http://127.0.0.1:5000/' + goods.img
            }
            goods_all.append(d)
        return jsonify({'code': 200, 'msg': '商品列表获取成功',
                        'data': goods_all})

    def post(self):
        # 添加商品
        args = request.json
        title = args.get('title')
        desc = args.get('desc')
        price = args.get('price')
        img = args.get('img')
        
        if not all([title, desc, price, img]):
            return jsonify({'code': 400, 'msg': '参数不完整'})
        goods = GoodsModel(title=title, price=price, desc=desc, img=img)
        db.session.add(goods)
        db.session.commit()
        return jsonify({'code': 200, 'msg': '添加成功'})


class GoodsInfoView(Resource):
    def get(self, id):
        # 获取一条商品
        goods_info = GoodsModel.query.get(id)   # 获取一条对象
        
        if not goods_info:
            return jsonify({'code': 400, 'msg': '商品不存在'})
        return jsonify({
            'code': 200,
            'msg': '商品获取成功',
            'data': {
                'id': goods_info.id,
                'title': goods_info.title,
                'desc': goods_info.desc,
                'price': str(goods_info.price),
                'img': '%s://%s/%s' % (request.scheme, request.host, goods_info.img),
            }
        })

    def put(self, id):
        # 修改一条商品
        args = request.json
        title = args.get('title')
        desc = args.get('desc')
        price = args.get('price')
        img = args.get('img')

        goods_info = GoodsModel.query.get(id)
        
        if not goods_info:
            return jsonify({'code': 400, 'msg': '商品不存在'})

        if title and title != goods_info.title:     # title不为空 并且修改后的值发生改变 才进行修改
            goods_info.title = title
        if desc and desc != goods_info.desc:
            goods_info.desc = desc
        if price and price != goods_info.price:
            goods_info.price = price
        if img and img != goods_info.img:
            goods_info.img = img

        db.session.commit()
        return jsonify({'code': 200, 'msg': '修改成功'})

    def delete(self, id):
        # 删除一条商品
        goods_info = GoodsModel.query.get(id)
        
        if not goods_info:
            return jsonify({'code': 400, 'msg': '商品不存在'})
        GoodsModel.query.filter(GoodsModel.id == id).delete()
        
        db.session.commit()
        return jsonify({'code': 200, 'msg': '删除成功'})


# 上传图片
class UploadView(Resource):
    def post(self):
        img = request.files.get('img')
        filename = datetime.strftime(datetime.now(), '%Y%m%d%H%M%S')
        filename += str(random.randint(100000, 999999))
        filename += '.'
        filename += img.filename.split('.')[-1]

        img.save('./static/%s' % filename)
        return jsonify({'code': 200, 'msg': '文件上传成功',
                        'data': {'filename': 'static/%s' % filename}})


api.add_resource(GoodsView, '/goods')
api.add_resource(GoodsInfoView, '/goods/<int:id>')
api.add_resource(UploadView, '/upload')

reqparse.RequestParser()        接收参数

from flask_restful import Api, Resource, reqparse

class PotView(Resource):
    def post(self):
        req = reqparse.RequestParser()
        # required 代表这个字段 必须传入,可以传入空字符串
        # nullable=false 意味着你不能输入空
        # help当校验不通过的时给用户返回什么提示
        req.add_argument('title', required=True, nullable=False, help='选项不能为空')
        req.add_argument('is_ok', type=int, default=0)
        req.add_argument('que_id', type=int, required=True, nullable=False, help='题干不能为空')
        args = req.parse_args()
        # 接收参数为 args['title']
        q = QueModel(**args)
        db.session.add(q)
        db.session.commit(q)