package com.example.demo.model.Client; import com.example.demo.model.User; import javax.persistence.Embeddable; import javax.persistence.JoinColumn; import javax.persistence.ManyToOne; import java.io.Serializable; @Embeddable public class ClientCompositeKey implements Serializable { @ManyToOne @JoinColumn(name="user_id") public User user; public ClientCompositeKey(User user) { this.user = user; } public ClientCompositeKey() { } public User getUser() { return user; } public void setUser(User user) { this.user = user; } }