JPA JoinColumn save id external entity class inside another entity class

Question

I have entityclass ProjectData. In this class I have UserData entity object. I use @JoinColumn annotation to get userData when I get ProjectData- it work properly. But if I create new ProjectData I don't know how to save userDataId to PRJ_USER_PM_ID column;

In table PROJECT I have id of user data. I try with additional attrbute projectUserid, but it seems to me it is not good solution.

@Entity
    @Table(name="PROJECT")
    public class ProjectData extends AbstractData {

        @OneToOne(fetch = FetchType.EAGER)
        @JoinColumn(name = "PRJ_USER_PM_ID", referencedColumnName = "USR_ID",   insertable = false, updatable = false )
        UserData user;

      /*@Column(name = "PRJ_USER_PM_ID")
        Long projectUserid; */
    }

Answer 1

Create a userData with required ID if you dont have it, and just set it to projectData:

projectData.setUserData (userData);

And then save projectData.