@Edward thanks for your contriubution..

I Resolved that!!

TypeOrm has a property on the OneToOne annotation, called primary, and if we set it to true, it will map the relation throught the primary key, exactly we get on use @MapsId on JPA Hibernate.

Ex (On Seller or Clients class):

 @OneToOne(() => Usuario, { primary: true, cascade: true })
 @JoinColumn({ name: 'OPD_id' })
 usuario: Usuario;

Its enough to create a generalization relation between classes (e.g User/Seller), joined by their id keys.

Something like @MapsId on JPA Hibernate does not exist in TypeOrm. Hibernate is a much more mature ORM.

In TypeOrm you can achieve the same result as follows:

1. Use @PrimaryColumn instead of @PrimaryGeneratedColumn on the related tables (sellers & clients in your case)

2. After @PrimaryColumn add @OneToOne relation to the main table (users in your case), and on @JoinColumn make the column name the same as the @PrimaryColumn name. This will give you a single column for the Primary Key and the Foreign Key relation

3. Add @BeforeInsert in each of the related table to copy the id from the main table (users) to the primary/foreign key of the other table (sellers & clients)

4. Use { "cascade": true } on the @OneToOne, so you only need to save the related table, the main table will be saved automatically first within the same transaction, then @BeforeInsert will copy the new key to the related table, then the related table will be saved

 import { Entity, PrimaryGeneratedColumn, Column, 
  OneToOne, JoinColumn, PrimaryColumn, BeforeInsert } from "typeorm";
    
  @Entity()
    export class users {
    @PrimaryGeneratedColumn()
    id: number;

    @Column()
    username: string;
}

 @Entity()
   export class clients {
    @PrimaryColumn()
    clientid: number;
    @OneToOne(() => users, { "cascade": true })
    @JoinColumn({ name: "clientid" } )  // This matches @PrimaryColumn name
    user: users;

    @BeforeInsert()
    newid() { this.clientid = this.user.id; }

    @Column()
    clientname: string;
}

  @Entity()
    export class sellers {
    @PrimaryColumn()
    sellerid: number;
    @OneToOne(() => users, { "cascade": true })
    @JoinColumn({ name: "sellerid" } )  // This matches @PrimaryColumn name
    user: users;

    @BeforeInsert()
    newid() { this.sellerid = this.user.id; }

    @Column()
    sellername: string;
}

Main code, to save User + Seller:

const connection = await createConnection();
const entityManager = connection.createEntityManager();

const user = new users();
const seller = new sellers();
seller.user = user;

user.username = "Giordano User";
seller.sellername = 'Giordano Seller';

await entityManager.save(seller);  // "user" saves automatically because of "cascade"