如何在 NestJS 中插入具有 OneToMany 关系的实体? [英] How to insert an entity with OneToMany relation in NestJS?

问题描述

typeorm 官方文档中描述了如何执行此操作 https://typeorm.io/#/many-to-one-one-to-many-relations.但是我不能用 Repository 和 insert 方法在 NestJS 中做同样的事情.

There is the description how to do this in typeorm official docs https://typeorm.io/#/many-to-one-one-to-many-relations. But I can't do the same in NestJS with Repository and insert method.

我写了这些实体(省略了其他列)

I have written these entities (other columns were omitted)

@Entity()
export class News {
  @OneToMany(type => NewsImage, image => image.news)
  public images: NewsImage[];
}

@Entity()
export class NewsImage {
  @ManyToOne(type => News, news => news.images)
  public news: News;
}

我试过这样的事情

function first() {
  const news = new News();
  const image = new NewsImage();
  news.images = [ image ];
  return from(this.newsRepo.insert(news))
    .pipe(
      switchMap(() => this.imageRepo.insert(image)),
    );
}

function second() {
  const news = new News();
  const image = new NewsImage();
  image.news = news;
  return from(this.imageRepo.insert(image))
    .pipe(
      switchMap(() => this.newsRepo.insert(news)),
    )
}

插入新闻和图片，但图片的newsId为null.

It inserts news and image, but image's newsId is null.

推荐答案

检查级联属性

@Entity()
export class News {
  @OneToMany(type => NewsImage, image => image.news, { cascade: ['insert', 'update'] })
  public images: NewsImage[];
}

然后如果你做类似的事情

Then if you do something like

let news = {
        images: [{
            date: "",
            etc: ""
        }],
        title: ""
    }

如果你调用 this.repository.save(news) 它将保存新闻和图像.还有更新.在 typeorm 文档上查看更多关于此的文档.

If then you call this.repository.save(news) it will save the news and the images. And updates too. Check more docs about this on typeorm docs.

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