Relations

Relations work a little differently in typegoose when compared to other relational ORMs such as sequelize or typeorm. You can read more about relations (references) in typegoose [here](https://mongoosejs.com/docs/populate .html)

There are multiple ways to set of references in Typegoose. These are intended as a starting point.

Filtering on references is not supported by Typegoose.

One to Many/Many To One Example

To set up a one to many/many to one relationship in Typegoose, you will store a reference in your document. For example, lets add sub tasks to our todo items by storing a todoItem ref on our subTask and an array of sub-tasks on our todoItem entity.

Todo Item
Subtask

todo-item/todo-item.entity.ts

import { Prop, modelOptions } from '@typegoose/typegoose'
import { Base } from '@typegoose/typegoose/lib/defaultClasses'

@modelOptions({ schemaOptions: { timestamps: true } })
export class TodoItemEntity extends Base {

  @Prop({ required: true })
  title!: string

  @Prop()
  description?: string

  @Prop({ required: true })
  completed!: boolean

  @Prop({ default: Date.now })
  createdAt!: Date

  @Prop({ default: Date.now })
  updatedAt!: Date

  @Prop({ default: 0 })
  priority!: number

  @Prop({ ref: () => SubTaskEntity })
  subTasks: Ref<SubTaskEntity>[]

  @Prop()
  createdBy?: string

  @Prop()
  updatedBy?: string
}

sub-task/sub-task.entity.ts

import { Prop, modelOptions, Ref } from '@typegoose/typegoose'
import { Base } from '@typegoose/typegoose/lib/defaultClasses'

@modelOptions({ schemaOptions: { timestamps: true } })
export class SubTaskEntity extends Base {

  @Prop({ required: true })
  title!: string

  @Prop()
  description?: string

  @Prop({ required: true })
  completed!: boolean

  @Prop({ ref: () => TodoItemEntity, required: true })
  todoItem!: Ref<TodoItemEntity>

  @Prop()
  createdAt!: Date

  @Prop()
  updatedAt!: Date

  @Prop()
  createdBy?: string

  @Prop()
  updatedBy?: string
}

Now that we have the relationships defined, we can add the @Relation and @Connection to our DTOs

Todo Item
Subtask

todo-item/todo-item.dto.ts

import { FilterableField, IDField, KeySet, Connection } from '@ptc-org/nestjs-query-graphql'
import { ObjectType, ID, GraphQLISODateTime, Field } from '@nestjs/graphql'
import { SubTaskDTO } from '../../sub-task/dto/sub-task.dto'

@ObjectType('TodoItem')
@KeySet(['id'])
// disable the remove because mongoose does not support removing a virtual

@Connection('subTasks', () => SubTaskDTO, { update: { enabled: true } })
export class TodoItemDTO {

  @IDField(() => ID)
  id!: string

  @FilterableField()
  title!: string

  @FilterableField({ nullable: true })
  description?: string

  @FilterableField()
  completed!: boolean

  @FilterableField(() => GraphQLISODateTime)
  createdAt!: Date

  @FilterableField(() => GraphQLISODateTime)
  updatedAt!: Date

  @Field()
  age!: number

  @FilterableField()
  priority!: number

  @FilterableField({ nullable: true })
  createdBy?: string

  @FilterableField({ nullable: true })
  updatedBy?: string
}

sub-task/sub-task.dto.ts

import { FilterableField, IDField, KeySet, Relation } from '@ptc-org/nestjs-query-graphql'
import { ObjectType, ID, GraphQLISODateTime } from '@nestjs/graphql'
import { TodoItemDTO } from '../../todo-item/dto/todo-item.dto'

@ObjectType('SubTask')
@KeySet(['id'])
// disable the remove because a sub task cannot exist without a todoitem

@Relation('todoItem', () => TodoItemDTO, { update: { enabled: true } })
export class SubTaskDTO {

  @IDField(() => ID)
  id!: string

  @FilterableField()
  title!: string

  @FilterableField({ nullable: true })
  description?: string

  @FilterableField()
  completed!: boolean

  @FilterableField(() => GraphQLISODateTime)
  createdAt!: Date

  @FilterableField(() => GraphQLISODateTime)
  updatedAt!: Date

  @FilterableField({ nullable: true })
  createdBy?: string

  @FilterableField({ nullable: true })
  updatedBy?: string
}

Many To Many Example

In this example, we’ll add tags to todoItems by storing an array of tag references on the todoItems.

Todo Item
Tag

todo-item/todo-item.entity.ts

import { Prop, modelOption, Ref } from '@typegoose/typegoose'
import { Base } from '@typegoose/typegoose/lib/defaultClasses'

@modelOptions({ schemaOptions: { timestamps: true } })
export class TodoItemEntity extends Base {

  @Prop({ required: true })
  title!: string

  @Prop()
  description?: string

  @Prop({ required: true })
  completed!: boolean

  @Prop({ default: Date.now })
  createdAt!: Date

  @Prop({ default: Date.now })
  updatedAt!: Date

  @Prop({ ref: () => TagEntity })
  tags!: Ref<TagEntity>[]

  @Prop({ default: 0 })
  priority!: number

  @Prop()
  createdBy?: string

  @Prop()
  updatedBy?: string

  public get id(): string {
    // eslint-disable-next-line no-underscore-dangle
    return this._id.toHexString()
  }
}

tag/tag.entity.ts

import { Base } from '@typegoose/typegoose/lib/defaultClasses'
import { Prop, modelOptions, Ref } from '@typegoose/typegoose'
import { Types } from 'mongoose'
import { TodoItemEntity } from '../todo-item/todo-item.entity'

@modelOptions({
  schemaOptions: {
    timestamps: true,
    collection: 'tags',
    toObject: { virtuals: true }
  }
})
export class TagEntity implements Base {

  _id!: Types.ObjectId

  id!: string

  @Prop({ required: true })
  name!: string

  @Prop()
  createdAt!: Date

  @Prop()
  updatedAt!: Date

  @Prop()
  createdBy?: string

  @Prop()
  updatedBy?: string

  @Prop({
    ref: 'TodoItemEntity',
    localField: '_id',
    foreignField: 'tags'
  })
  todoItems?: Ref<TodoItemEntity>[]
}

Now that we have the relationship defined, we can add the @Connection to our DTOS

Todo Item
Tag

todo-item/todo-item.dto.ts

import { FilterableField, IDField, KeySet, Connection } from '@ptc-org/nestjs-query-graphql'
import { ObjectType, ID, GraphQLISODateTime, Field } from '@nestjs/graphql'
import { TagDTO } from '../../tag/dto/tag.dto'

@ObjectType('TodoItem')
@KeySet(['id'])
@Connection('tags', () => TagDTO)
export class TodoItemDTO {

  @IDField(() => ID)
  id!: string

  @FilterableField()
  title!: string

  @FilterableField({ nullable: true })
  description?: string

  @FilterableField()
  completed!: boolean

  @FilterableField(() => GraphQLISODateTime)
  createdAt!: Date

  @FilterableField(() => GraphQLISODateTime)
  updatedAt!: Date

  @Field()
  age!: number

  @FilterableField()
  priority!: number

  @FilterableField({ nullable: true })
  createdBy?: string

  @FilterableField({ nullable: true })
  updatedBy?: string
}

tag/tag.dto.ts

import { FilterableField, IDField, KeySet, Connection } from '@ptc-org/nestjs-query-graphql'
import { ObjectType, ID, GraphQLISODateTime } from '@nestjs/graphql'
import { TodoItemDTO } from '../../todo-item/dto/todo-item.dto'

@ObjectType('Tag')
@KeySet(['id'])
// disable update and remove since it is a virtual in the entity

@Connection('todoItems', () => TodoItemDTO)
export class TagDTO {

  @IDField(() => ID)
  id!: string

  @FilterableField()
  name!: string

  @FilterableField(() => GraphQLISODateTime)
  createdAt!: Date

  @FilterableField(() => GraphQLISODateTime)
  updatedAt!: Date

  @FilterableField({ nullable: true })
  createdBy?: string

  @FilterableField({ nullable: true })
  updatedBy?: string
}

Discriminators

Typegoose supports mongoose discriminators. nestjs-query provides support for them through the NestjsQueryTypegooseModule. To use discriminators you need to define them in your NestjsQueryTypegooseModule.forFeature call. When working with discriminators, nestjs-query requires you to provide a service class for each discriminated entity. This is necessary for the auto-generated resolvers to be created correctly. These service classes are also the perfect place to add any custom business logic for your discriminated entities.

todo-item/todo-item.module.ts

import { NestjsQueryGraphQLModule } from '@ptc-org/nestjs-query-graphql'
import { NestjsQueryTypegooseModule, TypegooseQueryService } from '@ptc-org/nestjs-query-typegoose'
import { Module } from '@nestjs/common'
import { TodoItemEntity } from './entities/todo-item.entity'
import { TodoTaskEntity } from './entities/todo-task.entity'
import { TodoAppointmentEntity } from './entities/todo-appointment.entity'
import { TodoItemDTO } from './dto/todo-item.dto'
import { TodoTaskDTO } from './dto/todo-task.dto'
import { TodoAppointmentDTO } from './dto/todo-appointment.dto'
import { CreateTodoTaskInput } from './dto/create-todo-task.input'
import { CreateTodoAppointmentInput } from './dto/create-todo-appointment.input'
import { InjectModel } from '@m8a/nestjs-typegoose'
import { ReturnModelType } from '@typegoose/typegoose'

const typegooseModule = NestjsQueryTypegooseModule.forFeature([
  {
    typegooseClass: TodoItemEntity,
    discriminators: [{ typegooseClass: TodoTaskEntity }, { typegooseClass: TodoAppointmentEntity }]
  }
])

class TodoTaskEntityService extends TypegooseQueryService<TodoTaskEntity> {

  constructor(@InjectModel(TodoTaskEntity) readonly model: ReturnModelType<typeof TodoTaskEntity>) {
    super(model)
  }
}

class TodoAppointmentService extends TypegooseQueryService<TodoAppointmentEntity> {

  constructor(@InjectModel(TodoAppointmentEntity) readonly model: ReturnModelType<typeof TodoAppointmentEntity>) {
    super(model)
  }
}

@Module({
  imports: [
    NestjsQueryGraphQLModule.forFeature({
      imports: [typegooseModule],
      resolvers: [
        {
          DTOClass: TodoItemDTO,
          EntityClass: TodoItemEntity,
          create: { disabled: true }, // Disable create for the base entity
          update: { disabled: true } // Disable update for the base entity
        },
        {
          DTOClass: TodoTaskDTO,
          EntityClass: TodoTaskEntity,
          // Tell the resolver to use our custom input for the create operation
          CreateDTOClass: CreateTodoTaskInput,
          ServiceClass: TodoTaskEntityService
        },
        {
          DTOClass: TodoAppointmentDTO,
          EntityClass: TodoAppointmentEntity,
          // Tell the resolver to use our custom input for the create operation
          CreateDTOClass: CreateTodoAppointmentInput,
          ServiceClass: TodoAppointmentService
        }
      ],
      services: [TodoTaskEntityService, TodoAppointmentService]
    })
  ]
})
export class TodoItemModule {}

Introduction

Concepts

Persistence

Utilities

Project

Migration Guides

One to Many/Many To One Example

Many To Many Example

Discriminators

​One to Many/Many To One Example

​Many To Many Example

​Discriminators

One to Many/Many To One Example

Many To Many Example

Discriminators