如何在单独的文件中链接两个猫鼬模式？答案

【问题标题】：How to link two mongoose schemas in seperate files?如何在单独的文件中链接两个猫鼬模式？
【发布时间】：2021-02-14 02:37:38
【问题描述】：

我正在创建一个基本的银行应用程序，但在单独的文件中导入 mongoose 架构时遇到问题。我有两个模式，一个用户和一个事务。我的用户模式有一个名为 transactionHistory 的字段，它是一个事务对象数组，我的事务模式有发送者和接收者字段，它们都是用户对象。

Transaction/model.js

import mongoose from "mongoose";
import { UserSchema } from "./../User/model";

export const TransactionSchema = new mongoose.Schema(
    {
        sender: { type: UserSchema, required: true },
        receiver: { type: UserSchema, required: true },
        time: { type: Date, required: true },
        amount: { type: Number, required: true },
    },
    { collection: "transactions" }
);

export const TransactionModel = new mongoose.model(
    "Transaction",
    TransactionSchema
);

用户/model.js

import mongoose from "mongoose";
import { TransactionSchema } from "./../Transaction/model";

export const UserSchema = new mongoose.Schema(
    {
        firstName: { type: String, required: true },
        lastName: { type: String, required: true },
        age: { type: Number, required: true },
        email: { type: String, required: true },
        password: { type: String, require: true },
        balance: { type: Number, required: true },
        transactionHistory: {
            type: [TransactionSchema],
            default: undefined,
            required: true,
        },
    },
    { collection: "users" }
);

export const UserModel = new mongoose.model("User", UserSchema);

当我尝试运行此代码时，它会抛出错误

      throw new TypeError('Invalid value for schema path `' + fullPath +
      ^

TypeError: Invalid value for schema path `sender.type`, got value "undefined"
    at Schema.add (/home/typicalfork/Documents/Projects/typical-bank/node_modules/mongoose/lib/schema.js:473:13)
    at Schema.add (/home/typicalfork/Documents/Projects/typical-bank/node_modules/mongoose/lib/schema.js:507:12)
    at new Schema (/home/typicalfork/Documents/Projects/typical-bank/node_modules/mongoose/lib/schema.js:127:10)
    at Object.<anonymous> (/home/typicalfork/Documents/Projects/typical-bank/src/Transaction/model.js:4:34)
    at Module._compile (node:internal/modules/cjs/loader:1083:30)
    at Module._compile (/home/typicalfork/Documents/Projects/typical-bank/node_modules/pirates/lib/index.js:99:24)
    at Module._extensions..js (node:internal/modules/cjs/loader:1112:10)
    at Object.newLoader [as .js] (/home/typicalfork/Documents/Projects/typical-bank/node_modules/pirates/lib/index.js:104:7)
    at Module.load (node:internal/modules/cjs/loader:948:32)
    at Function.Module._load (node:internal/modules/cjs/loader:789:14)
    at Module.require (node:internal/modules/cjs/loader:972:19)
    at require (node:internal/modules/cjs/helpers:88:18)
    at Object.<anonymous> (/home/typicalfork/Documents/Projects/typical-bank/src/User/model.js:2:1)
    at Module._compile (node:internal/modules/cjs/loader:1083:30)
    at Module._compile (/home/typicalfork/Documents/Projects/typical-bank/node_modules/pirates/lib/index.js:99:24)
    at Module._extensions..js (node:internal/modules/cjs/loader:1112:10)

奇怪的是，当我像这样将用户模式复制到 Transaction/model.js 时：

import mongoose from "mongoose";
// import { UserSchema } from "./../User/model";

export const UserSchema = new mongoose.Schema(
    {
        firstName: { type: String, required: true },
        lastName: { type: String, required: true },
        age: { type: Number, required: true },
        email: { type: String, required: true },
        password: { type: String, require: true },
        balance: { type: Number, required: true },
        transactionHistory: {
            type: [TransactionSchema],
            default: undefined,
            required: true,
        },
    },
    { collection: "users" }
);

export const TransactionSchema = new mongoose.Schema(
    {
        sender: { type: UserSchema, required: true },
        receiver: { type: UserSchema, required: true },
        time: { type: Date, required: true },
        amount: { type: Number, required: true },
    },
    { collection: "transactions" }
);

export const TransactionModel = new mongoose.model(
    "Transaction",
    TransactionSchema
);

一切都按预期进行。这让我相信我以某种方式错误地导入了架构。

【问题讨论】：

标签： javascript node.js mongodb mongoose mongoose-schema

【解决方案1】：

问题是您在两个文件中都有 2 个导出，您只需要 1 个导出删除 export 定义函数的关键字

const UserSchema = new mongoose.Schema() //<-- export keyword removed

export const UserModel = new mongoose.model("User", UserSchema); //<-- Exporting here

您需要修复两个文件。

【讨论】：