我如何使用猫鼬中间件进行填充

Question

  {
    cartItems: [
      {
        product: { type: mongoose.Schema.Types.ObjectId, ref: "product" },
        quantity: Number,
        color: String,
        price: Number,
      },
    ],
    totalPrice: Number,
    totalPriceAfterDiscount: Number,
    user: {
      type: mongoose.Schema.ObjectId,
      ref: "user",
    },
  },
  { timestamps: true }
);

// @desc query mongoose middleware to populate
CartSchema.pre(/find/, function (next) {
  this.populate("user");
  next();
});```

it throw this error

MissingSchemaError：尚未为模型“用户”注册架构。 使用 mongoose.model(名称，模式) 在 Connection.model (/home/melewasy/projects/full-E-commerce/node_modules/mongoose/lib/connection.js:1236:13) 在 _getModelFromConn （/home/melewasy/projects/full-E-commerce/node_modules/mongoose/lib/helpers/populate/getModelsMapForPopulate.js:581:15） 在addModelNamesToMap（/home/melewasy/projects/full-E-commerce/node_modules/mongoose/lib/helpers/populate/getModelsMapForPopulate.js:507:17） 在 getModelsMapForPopulate (/home/melewasy/projects/full-E-commerce/node_modules/mongoose/lib/helpers/populate/getModelsMapForPopulate.js:198:7) 在填充（/home/melewasy/projects/full-E-commerce/node_modules/mongoose/lib/model.js:4679:21） 在 _populate (/home/melewasy/projects/full-E-commerce/node_modules/mongoose/lib/model.js:4639:5) 在/home/melewasy/projects/full-E-commerce/node_modules/mongoose/lib/model.js:4616:5 在promiseOrCallback（/home/melewasy/projects/full-E-commerce/node_modules/mongoose/lib/helpers/promiseOrCallback.js:11:14） 在 Mongoose._promiseOrCallback （/home/melewasy/projects/full-E-commerce/node_modules/mongoose/lib/index.js:1266:10） 在 Model.populate (/home/melewasy/projects/full-E-commerce/node_modules/mongoose/lib/model.js:4614:23)"

i tried this line instead of mongoose middleware

let x = await Cart.findById(cart._id).populate("user");

Answer 1

导入用户架构

const User = require("file_path")

并将其添加到填充方法中

let x = await Cart.findById(cart._id).populate("user", User);

Answer 2

你修好了吗？我有同样的错误