NestJs使用连接表更新多对多关系 [英] NestJs update Many-To-Many relation with join table

问题描述

我有两个实体-财产和所有者.一个财产可以有很多所有者，而所有者可以有很多财产.对于联接，请使用property_owner表.如何使用NestJS/TypeORM更新这种多对多关系?

I have two entities - Property and Owner. One Property can have a lot of Owners and Owner can have a lot of Properties. For join use property_owner table. How to update this many-to-many relation using NestJS/TypeORM?

@Entity('property')
export class Property extends EntityModel {

    @Column({ length: 255, nullable: false })
    name: string;

    @ManyToMany(type => Owner, { cascade: true })
    @JoinTable({
        name: 'property_owner',
        joinColumn: { name: 'propertyId', referencedColumnName: 'id'},
        inverseJoinColumn: { name: 'ownerId', referencedColumnName: 'id'},
    })
    owners: Owner[];
}


@Entity('owner')
export class Owner extends EntityModel {

    @Column({ length: 255, nullable: false })
    name: string;

    @ManyToMany(type => Property, { cascade: true })
    @JoinTable({
        name: 'property_owner',
        joinColumn: { name: 'ownerId', referencedColumnName: 'id'},
        inverseJoinColumn: { name: 'propertyId', referencedColumnName: 'id'},
    })
    properties: Property[];
}

以下用于保存和更新服务的方法:

Below my service's methods for save and update:

public create(req: Request): Promise<Dto> {
    const dto: CreateDto = {
      ...req.body,
      owners: this.formatJoinData(req.body.owners) //[1,2,3] => [{id:1},{id:2},{id:3}]
    };

    const entity = Object.assign(new Entity(), dto);
    return this.repo.save(entity);
  }

  public update(req: Request): Promise<UpdateResult> {
    const dto: EditDto = {
      ...req.body,
      owners: this.formatJoinData(req.body.owners) //[1,2,3] => [{id:1},{id:2},{id:3}]
    };

    const id = req.params.id;
    const entity = Object.assign(new Entity(), dto);
    return this.repo.update(id, entity);
  }

保存新媒体资源效果很好，但是当我尝试更新媒体资源时出现错误

Saving new Property work fine, but when I try update property I get error

 [ExceptionsHandler] column "propertyId" of relation "property" does not exist

在两种情况下，所有者数据都看起来像[{id:1}，{id:2}，{id:3}].我认为保存/更新方法结果存在问题.保存方法返回给我们具有ID的实体，更新方法返回给我们不包含实体ID的UpdateResult.但是也许我们可以在某个地方变换/另外定义该值...

Owners data in both cases looks like [{id:1},{id:2},{id:3}]. I think problem in save/update methods results. Save method return to us Entity with id and update method return to us UpdateResult which not contain Entity id. But may be we can transform/additionally define this value somewhere...

推荐答案

我找到了解决方案.需要调用保存方法而不是更新.就我而言，更新将类似于

I found solution. Need to call save method instead update. In my case update will be looks like

import {plainToClass} from 'class-transformer';

public async update(req: Request): Promise<Dto> {

    const found = await this.repo.findOneOrFail(req.params.id, {
                    relations: ['owners', 'electricMeter'],
                  });

    const dto = {
      ...found,
      ...req.body,
      owners: this.formatJoinData(req.body.owners) //[1,2,3] => [{id:1},{id:2},{id:3}]
      updatedBy: this.getUser(req),
      updatedDate: Date.now(),
    };

    return this.repo.save(plainToClass(Entity, dto));
  }

此代码可以改进，但认为主要思想很清楚.

This code can be improved, but think that main idea is clear.

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