How to find relations and sub-relations?

Question

I am new to TypeOrm and NestJS. Can you suggest to me how to get relations and sub relations in my code? I don`t understand how to get all relations Board->Columns-Cards. Thanks

Entity({ name: 'boards' })
export class Board {
  @PrimaryGeneratedColumn()
  public id!: number;

  @Clmn({ type: 'varchar', length: 120 })
  public name: string;

  @CreateDateColumn({ type: 'timestamp' })
  public created_at!: Date;

  @UpdateDateColumn({ type: 'timestamp' })
  public updated_at!: Date;

  @OneToMany('Column', (column: Column) => column.board_id, {
    onDelete: 'CASCADE',
    onUpdate: 'CASCADE',
  })
  columns: Array<Column>;
}

@Entity({ name: 'columns' })
export class Column {
  @PrimaryGeneratedColumn()
  public id!: number;

  @Colmn({ type: 'varchar', length: 120 })
  public name: string;

  @CreateDateColumn({ type: 'timestamp' })
  public created_at!: Date;

  @UpdateDateColumn({ type: 'timestamp' })
  public updated_at!: Date;

  @ManyToOne(() => Board, (board: Board) => board.columns)
  @JoinColumn({ name: 'board_id' })
  board_id: number;

  @OneToMany('Card', (card: Card) => card.column_id, {
    onDelete: 'CASCADE',
    onUpdate: 'CASCADE',
  })
  columns: Array<Column>;
}

@Entity({ name: 'cards' })
export class Card {
  @PrimaryGeneratedColumn()
  public id!: number;

  @Colmn({ type: 'varchar', length: 120 })
  public name: string;

  @Colmn({ type: 'varchar', length: 120 })
  public text: string;

  @CreateDateColumn({ type: 'timestamp' })
  public created_at!: Date;

  @UpdateDateColumn({ type: 'timestamp' })
  public updated_at!: Date;

  @ManyToOne(() => Column, (card: Column) => card.columns)
  @JoinColumn({ name: 'column_id' })
  column_id: number;
}

I check all docs and answers in stack overflow? but don`t understand how to decide this problem. I try this code this results in an error: Relation "columns.card" was not found; please check if it is correct and really exists in your entity.

public async getBoardWithContent(board_id: number) {
    return await this.boardsRepository.find({
      where: { id: board_id },
      relations: ['columns', 'columns.card'],
    });
  }

Answer 1

Your Column.columns attribute is very strange, you seem to be mixing up cards and columns in your model.

I think this should be:

@OneToMany(() => Card, (card: Card) => card.column_id, {
  onDelete: 'CASCADE',
  onUpdate: 'CASCADE',
})
cards: Array<Card>;

Then. requesting:

public async getBoardWithContent(board_id: number) {
  return await this.boardsRepository.find({
    where: { id: board_id },
    relations: ['columns', 'columns.cards'],
  });
}

should work.