How to map joined table column to an entity's field in TypeORM - postgresql

Question

There are two entities as follow:
// user.entity.ts
#Entity()
export class User extends BaseEntity {
#PrimaryGeneratedColumn()
id: number;
#Column()
#RelationId((user: User) => user.group)
groupId: number;
#Column()
fullName: string;
#Column()
email: string;
#Column()
passwordHash: string;
#ManyToOne(type => Group, group => group.users)
#JoinColumn()
group: Group;
isOwner: boolean;
}
// group.entity.ts
#Entity()
export class Group extends BaseEntity {
#PrimaryGeneratedColumn()
id: number;
#Column()
name: string;
#Column({ default: false })
isOwner: boolean;
#OneToMany(type => User, user => user.group)
users: User[];
}
I'd like to map the isOwner value of Group to isOwner of User
I tried:
async findOneById(id: number): Promise<User> {
return await User.createQueryBuilder('user')
.leftJoinAndMapOne('user.isOwner', 'user.group', 'group')
.select(['user.id', 'user.fullName', 'user.email', 'group.isOwner'])
.getOne();
}
the result was:
It is possible to achieve that by using #AfterLoad() or with JS or with raw query.
BUT
Is it possible to implement that using the orm on the query level?

Answer 1

Something like that could be as a solution:
findOneById(id: number): Promise<User> {
return User.createQueryBuilder('user')
.leftJoinAndMapOne('user.isOwner', 'user.group', 'group')
.select(['user.id', 'user.fullName', 'user.email', 'group.isOwner AS user.isOwner']) // or probably 'group.isOwner AS user_isOwner'
.getOne();
}
And you could look at this answer, hope it would be helpful