如何在 nestjs 中填充 mongoose 引用？

Question

我定义了人物和故事模式：

    @Schema()
    export class Person extends Document {
      @Prop()
      name: string;
    }
    export const PersonSchema = SchemaFactory.createForClass(Person);
    
    
    @Schema()
    export class Story extends Document {
    
      @Prop()
      title: string;
    
      @Prop()
      author:  { type: MongooseSchema.Types.ObjectId , ref: 'Person' }
    
    }
    export const StorySchema = SchemaFactory.createForClass(Story);

在我的服务中，我实现了保存和读取功能：

        async saveStory(){
        const newPerson = new this.personModel();
        newPerson.name  = 'Ian Fleming';
        await newPerson.save();
        const newStory  = new this.storyModel();
        newStory.title = 'Casino Royale';
        newStory.author = newPerson._id;
        await newStory.save();
      }
    
      async readStory(){
        const stories = await this.storyModel.
            findOne({ title: 'Casino Royale' })
        console.log('stories ',stories);
      }

当我运行 readStory() 时，我得到以下输出：

     stories  {
      _id: 5f135150e46fa5256a3a1339,
      title: 'Casino Royale',
      author: 5f135150e46fa5256a3a1338,
      __v: 0
    }

当我将 populate('author') 添加到我的查询时，我得到的作者为 null:

     stories  {
      _id: 5f135150e46fa5256a3a1339,
      title: 'Casino Royale',
      author: null,
      __v: 0
    }

如何使用引用的个人文档填充作者字段？

Answer 1

找到了。我的错误在于定义架构。应该是：

@Schema()
export class Story extends Document {
  @Prop()
  title: string;
    
  @Prop({ type: MongooseSchema.Types.ObjectId , ref: 'Person' })
  author:  MongooseSchema.Types.ObjectId  
}

Answer 2

经过大量阅读和测试 nestjs 中的 mongoose 引用。我认为可以改进接受的答案。我将分两步展示这一点。第一步是显示 MongooseSchema 的声明，并包括 @illnr 关于作者属性使用 Types.ObjectId 而不是 MongooseSchema.Types.ObjectId.

的评论

import { Prop, Schema, SchemaFactory } from '@nestjs/mongoose';
import { Document, Types, Schema as MongooseSchema } from 'mongoose';

@Schema()
export class Story extends Document {

  @Prop()
  title: string;

  @Prop({ type: MongooseSchema.Types.ObjectId , ref: 'Person' })
  author:  Types.ObjectId 

}

export const StorySchema = SchemaFactory.createForClass(Story);

作为第二步，我认为使用 Person class 作为作者属性的类型可以提高可读性，如此处所示。

import { Prop, Schema, SchemaFactory } from '@nestjs/mongoose';
import { Document, Types, Schema as MongooseSchema } from 'mongoose';
import { Person } from './person.schema'

@Schema()
export class Story extends Document {

  @Prop()
  title: string;

  @Prop({ type: MongooseSchema.Types.ObjectId , ref: 'Person' })
  author:  Person

}

export const StorySchema = SchemaFactory.createForClass(Story);

Answer 3

None 以上对我有用，我不得不使用 populate()。参考资料来自 https://dev.to/mossnana/nestjs-with-mongoose-populate-4mo7?signin=true

完整代码和结构示例 users.service.ts

import { User, UserDocument } from 'src/schemas/user.schema';
import { Role, RoleDocument } from 'src/schemas/role.schema';

...

constructor(
    @InjectModel(User.name) private userModel: Model<UserDocument>,
    @InjectModel(Role.name) private roleModel: Model<RoleDocument>,
    private roleService: RolesService
  ) {}


async findOne(id: string) {
    return await this.userModel.findOne({ _id: id }).populate('role', '', this.roleModel).exec();
}

user.schema.ts

import { Prop, Schema, SchemaFactory } from '@nestjs/mongoose';
import * as mongoose from 'mongoose';
import { Role } from './role.schema';

export type UserDocument = User & mongoose.Document;

@Schema()
export class User {
  @Prop({ required: true, type: String })
  email: string;

  @Prop({ type: String })
  name: string;

  @Prop({ type: mongoose.Schema.Types.ObjectId, ref: 'Role' })
  role: Role;
}

export const UserSchema = SchemaFactory.createForClass(User);

role.schema.ts

export type RoleDocument = Role & mongoose.Document;

@Schema()
export class Role {
  @Prop({ type: String, required: true, unique: true, index: true })
  name: string;

  @Prop({ type: [String], required: true })
  permissions: string[];
}

export const RoleSchema = SchemaFactory.createForClass(Role);

如何在 nestjs 中填充 mongoose 引用？

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