类型多到多关系joinColumns

Question

我对打字机还不熟悉，我正努力使这个口碑成为一种魅力。我对简单的实体没有什么大不了的:照片和相册。我有一个连接表来知道哪张照片在哪张相册里。

因此，我有以下几点：

import {
  Entity, PrimaryGeneratedColumn, Column, OneToMany, JoinTable,
} from 'typeorm';
import { PicturesModel } from '../pictures/pictures.model';

@Entity({
  name: 'T_ALBUM_AL',
  synchronize: true,
})
export class AlbumModel {
  @PrimaryGeneratedColumn({
    name: 'AL_id',
  })
  id: number;

  @Column({
    name: 'AL_name',
  })
  name: string;

  @Column({
    name: 'AL_created_at',
  })
  created_at: Date;

  @Column({
    name: 'AL_updated_at',
  })
  updated_at: Date;

  @JoinTable({
    name: 'TJ_PICTURE_ALBUM_PA',
    joinColumn: {
      name: 'PI_id',
      referencedColumnName: 'PI_id',
    },
  })
  @OneToMany(() => PicturesModel, (pictures: PicturesModel) => pictures.id)
  pictures: PicturesModel[]
}


import { Entity, PrimaryGeneratedColumn, Column } from 'typeorm';

@Entity({
  name: 'T_PICTURE_PI',
  synchronize: true,
})
export class PicturesModel {
  @PrimaryGeneratedColumn({
    name: 'PI_id',
  })
  id: number;

  @Column({
    name: 'PI_name',
  })
  name: string;

  @Column({
    name: 'PI_path',
  })
  path: string;

  @Column({
    name: 'PI_created_at',
  })
  created_at: Date;

  @Column({
    name: 'PI_updated_at',
  })
  updated_at: Date;

  @Column({
    name: 'PI_size',
  })
  size: number;
}

因此，我有一个如下的模型:注意，用户逻辑尚未实现。

​

我有一个非常小的控制器来获取相册，我想检索每一张相册和里面的每一张照片：

import { Request, Response } from 'express';
import { getRepository } from 'typeorm';

import { AlbumModel } from './album.model';

class Album {
  public static async getAlbums(_req: Request, res: Response): Promise<Response> {
    try {
      const picture = await getRepository(AlbumModel).find({ relations: ['pictures'] });
      return res.json(picture);
    } catch (e) {
      console.error(e);
      return res.json('fail');
    }
  }
}

export default Album;

当我调用这个控制器时，我得到以下错误:但是正确地指定了joinColumns

TypeError: Cannot read property 'joinColumns' of undefined
    at /<something>/src/query-builder/SelectQueryBuilder.ts:1500:61
    at Array.map (<anonymous>)
    at SelectQueryBuilder.createJoinExpression (/<something>/src/query-builder/SelectQueryBuilder.ts:1470:57)
    at SelectQueryBuilder.getQuery (/<something>/src/query-builder/SelectQueryBuilder.ts:54:21)
    at SelectQueryBuilder.QueryBuilder.getQueryAndParameters (/<something>/src/query-builder/QueryBuilder.ts:415:28)
    at SelectQueryBuilder.<anonymous> (/<something>/src/query-builder/SelectQueryBuilder.ts:1956:40)
    at step (/<something>/node_modules/tslib/tslib.js:139:27)
    at Object.next (/<something>/node_modules/tslib/tslib.js:120:57)
    at /<something>/node_modules/tslib/tslib.js:113:75

有什么想法吗？

Answer 1

我找到了答案，问题来自专辑实体。这个名字让我有点困惑。请注意以下部分：

    joinColumn: {
      name: 'PI_id',
      referencedColumnName: 'id',
   }

名称是数据库中的列名。

referencedColumnName是实体的“列”/ object属性

import {
  Entity, PrimaryGeneratedColumn, Column, JoinTable, ManyToMany,
} from 'typeorm';
import { PicturesModel } from '../pictures/pictures.model';

@Entity({
  name: 'T_ALBUM_AL',
  synchronize: true,
})
export class AlbumModel {
  @PrimaryGeneratedColumn({
    name: 'AL_id',
  })
  id: number;

  @Column({
    name: 'AL_name',
  })
  name: string;

  @Column({
    name: 'AL_created_at',
  })
  created_at: Date;

  @Column({
    name: 'AL_updated_at',
  })
  updated_at: Date;

  @ManyToMany(() => PicturesModel, (picture: PicturesModel) => picture.id)
  @JoinTable({
    name: 'TJ_PICTURE_ALBUM_PA',
    joinColumn: {
      name: 'PI_id',
      referencedColumnName: 'id',
    },
    inverseJoinColumn: {
      name: 'PI_id',
      referencedColumnName: 'id',
    },
  })
  pictures: PicturesModel[]
}

最后，这给了我想要的输出：

{
    "id":1,
   "name":"aa",
   "created_at":"2020-03-16T23:00:00.000Z",
   "updated_at":"2020-03-16T23:00:00.000Z",
   "pictures":[
      {
         "id":1,
         "name":"Pic 1",
         "path":"Path",
         "created_at":"2020-03-17T23:00:00.000Z",
         "updated_at":"2020-03-17T23:00:00.000Z",
         "size":"2"
      }
   ]
}