Question

在typeorm官方文档https://typeorm.io/#/many-to-one-one-to-many-relations中有关于如何执行此操作的描述。但是我无法使用df = read.table(text = ' grp date long lat rowid 1 1 1995-07-01 11 12 1 2 1 1995-07-05 3 0 2 3 1 1995-07-09 13 4 3 4 1 1995-07-13 4 25 4 5 2 1995-03-07 12 6 1 6 2 1995-03-10 3 27 2 7 2 1995-03-13 34 8 3 8 2 1995-03-16 25 9 4', h = TRUE)和Repository方法在NestJS中执行相同的操作。

我已经写了这些实体（省略了其他列）

insert

我已经尝试过类似的事情

@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;
}

它插入新闻和图片，但图片的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)), ) }是newsId。

Answer 1

声明new News()会创建一个新实体，但不会将其保存到数据库中。您首先需要insert或.save()对象news，然后将其添加到image。

async function first() {
  // you can .save() it however you want, the point is it must be saved to the db
  const news = await News.create({ title: 'Async rules the world' }).save()
  const image = new NewsImage()
  image.news = news // now news has an id from the database
  // ...
}

Answer 2

检查级联属性

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

然后，如果您执行类似的操作

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

如果您致电this.repository.save(news)，它将保存新闻和图像。并且也更新。在typeorm文档上查看有关此内容的更多文档。

如何在NestJS中插入具有OneToMany关系的实体？

2 个答案: