有关如何在typeorm官方文档https://typeorm.io/#/many-to-one-one-to-many-relations中执行此操作的说明。但我不能在使用Repository
和insert
方法的NestJS中做同样的事情。
我写了这些实体(其他列被省略)
@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;
}
我尝试过这样的事情
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)),
)
}
它插入新闻和图像,但图像的newsId
是null
。
声明new News()
会创建一个新实体,但不会将其保存到数据库中。你首先需要insert
或.save()
news
对象,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
// ...
}
检查级联属性
@Entity()
export class News {
@OneToMany(type => NewsImage, image => image.news, { cascade: ['insert', 'update'] })
public images: NewsImage[];
}
然后,如果你做的事情
let news = {
images: [{
date: "",
etc: ""
}],
title: ""
}
如果那时你打电话给this.repository.save(news)
它将保存新闻和图像。还有更新。在typeorm docs上查看更多有关此内容的文档。