How can I manage advanced relations in TypeORM?

How can I manage advanced relations in TypeORM?

In TypeORM, you can manage advanced relations using decorators like @OneToMany, @ManyToOne, and @ManyToMany. Would you like an example?

Yes, please provide an example of a ManyToMany relationship.

Sure! For a ManyToMany relationship, you can create two entities and use a join table. For instance, if you have User and Group, you can define it like this:

@Entity()
export class User {
  @PrimaryGeneratedColumn()
  id: number;

  @ManyToMany(() => Group, group => group.users)
  @JoinTable()
  groups: Group[];
}

@Entity()
export class Group {
  @PrimaryGeneratedColumn()
  id: number;

  @ManyToMany(() => User, user => user.groups)
  users: User[];
}

What if I want to add additional fields to the join table?

You can create a separate entity for the join table. For example:

@Entity()
export class UserGroup {
  @PrimaryGeneratedColumn()
  id: number;

  @ManyToOne(() => User, user => user.userGroups)
  user: User;

  @ManyToOne(() => Group, group => group.userGroups)
  group: Group;

  @Column()
  role: string; // Additional field
}

Thanks! This is really helpful.