Flask一对多增删改查

模型类

from flask_sqlalchemy import SQLAlchemy

db = SQLAlchemy()


class CategoryModel(db.Model):
    id = db.Column(db.Integer, primary_key=True, autoincrement=True)
    name = db.Column(db.String(100), comment="分类名")
    icon = db.Column(db.String(100), comment="图标")
    good = db.relationship("GoodsModel", backref="cate")


class GoodsModel(db.Model):
    id = db.Column(db.Integer, primary_key=True, autoincrement=True)
    name = db.Column(db.String(100), comment="商品名")
    price = db.Column(db.DECIMAL(10, 2), comment="价格")
    img = db.Column(db.String(100), comment="图片地址")
    cate_id = db.Column(db.Integer, db.ForeignKey("category_model.id"), comment="分类标题")

展示

class GoodView(Resource):
    def get(self):
        req = reqparse.RequestParser()
        req.add_argument("cate_id")
        args = req.parse_args()
        cate_id = args["cate_id"]

        cate = CategoryModel.query.get(cate_id)
        
        if not cate:
            return jsonify({
                "code": 400,
                "msg": "分类标题不存在"
            })

        if cate_id:
            good_list = GoodsModel.query.filter(GoodsModel.cate_id == id).all()
        else:
            good_list = GoodsModel.query.all()

        temp = []
        for i in good_list:
            temp_dict = {
                "id": i.id,
                "name": i.name,
                "price": str(i.price),
                "img": 'http://127.0.0.1:5000' + i.img,
                "cate": i.cate.name
            }
            temp.append(temp_dict)
        return jsonify({
            "code": 200,
            "msg": "数据展示成功",
            "data": temp
        })

添加

    def post(self):
        req = reqparse.RequestParser()
        req.add_argument("name")
        req.add_argument("price")
        req.add_argument("img")
        req.add_argument("cate_id")
        args = req.parse_args()
        name = args["name"]
        price = args["price"]
        img = args["img"]
        cate_id = args["cate_id"]
        if not all([name, price, img]):
            return jsonify({
                "code": 400,
                "msg": "数据不能为空"
            })
        cate = CategoryModel.query.get(cate_id)
        if not cate:
            return jsonify({
                "code": 400,
                "msg": "分类标题不存在"
            })

        # 三种写法
        # 1.
        good = GoodsModel(name=name, price=price, img=img, cate_id=cate_id)
        # 2.
        # good = GoodsModel(name=name, price=price, img=img, cate=cate)
        # 3.
        # good = GoodsModel(**args)
        db.session.add(good)
        db.session.commit()
        return jsonify({
            "code": 200,
            "msg": "添加成功"
        })

修改

class OneGoodView(Resource):
    def put(self, id):
        req = reqparse.RequestParser()
        req.add_argument("name")
        req.add_argument("price")
        req.add_argument("img")
        req.add_argument("cate_id")
        args = req.parse_args()
        name = args["name"]
        price = args["price"]
        img = args["img"]
        cate_id = args["cate_id"]

        cate = CategoryModel.query.get(cate_id)
        if not cate:
            return jsonify({
                "code": 400,
                "msg": "分类标题不存在"
            })

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

        if name:
            good.name = name
        if price:
            good.price = price
        if img:
            good.img = img
        if cate_id:
            good.cate_id = cate_id

        db.session.commit()

        return jsonify({
            "code": 200,
            "msg": "修改成功"
        })

删除

    def delete(self, id):
        good = GoodsModel.query.get(id)
        if not good:
            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": "商品删除成功"
        })


api.add_resource(GoodView, "/good")
api.add_resource(OneGoodView, "/good/<int:id>")