无法在用户愿望清单键中附加多个项目

Question

这是我的前端代码。最初我从令牌中获取用户，令牌存在于本地存储中，然后是更新用户的代码和获取更新数据库中的用户的代码。

     let token = JSON.parse (localStorage.getItem ('token'));
        
        async function addtoWishlist (id) {
          let temp = await findId ();
          let user = await temp.json ();
          let wishlistArray = user.wishItems;
          console.log ('wishlistArray:', wishlistArray);
        
          wishlistArray.push (id);
          let dts = {
            wishItems: wishlistArray,
          };
          let data_to_send = JSON.stringify (dts);
        
          fetch (`http://localhost:2233/*/user/add`, {
            method: 'PATCH',
            body: data_to_send,
            headers: {
              'Content-Type': 'application/json',
              Authorization: `Bearer ${token}`,
            },
          })
            .then (k => {
              return k.json ();
            })
            .then (res => {
              console.log (res);
            })
            .catch (err => {
              console.log (err);
            });
        }
        
        async function findId () {
          let user = await fetch (`http://localhost:2233/*/user`, {
            headers: {
              'Content-Type': 'application/json',
        
              Authorization: `Bearer ${token}`,
            },
          });
        
          return user;
        }

控制器代码

app.get ('/*/user', authenticate, async (req, res) => {
  const user = req.user.user;

  return res.send (user);
});

app.patch ('/*/user/add', authenticate, async (req, res) => {
  try {
    console.log ('inside patch');

    let user = req.user.user;
    console.log ('user:', user);
    console.log (req.body);

    user = await User.findByIdAndUpdate (user._id, req.body, {
      new: true,
    })
      .lean ()
      .exec ();
    console.log ('after-user', user);
    return res.send (user);
  } catch (e) {
    return res.send (e.message);
  }
});

用户架构如下所示

const userSchema = new Schema (
  {
    fullName: {type: String, required: false},
    email: {type: String, required: true},
    password: {type: String, required: true},
    username: {type: String, required: true},
    mobile: {type: Number, required: true},
    description: {type: String, required: true},
    bagItems: [
      {
        productId: {
          type: Schema.Types.ObjectId,
          ref: 'product',
          required: false,
        },
        count: {type: Number, required: false},
      },
    ],
    wishItems: [
      {
        type: Schema.Types.ObjectId,
        ref: 'product',
      },
    ],
  },
  {
    versionKey: false,
    timestamps: true,
  }
);

** 每当我将项目添加到愿望清单时，它都会替换已经存在的项目...................... ..................................................... ..................................................... ..................................................... ..................................................... ..................................................... ....**

Answer 1

你需要使用$push operator

user = await User.findByIdAndUpdate (user._id, { $push: req.body }, { ...

确保req.body 仅具有wishItems 属性，没有别的。