hibernate 多對一，一對多

多對一關聯：還是拿Husband 和Wife類，印度可以一個丈夫娶多個老婆.

@Entity
public class Husband {
    private int id;
    private String name;
     @Id
     @GeneratedValue
    public int getId() {
        return id;
    }
    //其他get、set省略》。。
}

@Entity
public class Wife {
    private int id;
    private String name;
    //多個老婆一個丈夫，肯定要依靠丈夫，跟丈夫沒有關聯只能餓死了。所以要關聯起來。
    private Husband husband;

    @Id
    @GeneratedValue
    public int getId() {
        return id;
    }
    @ManyToOne//多對一..這樣就可以了
    public Husband getHusband() {
        return husband;
    }
    //其他get、set省略》。。
}

hibernate 一對多。一個丈夫 ，多個老婆。

@Entity
public class Husband {
    private int id;
    private String name;
    //老婆太多了，放到set集合裏面方便管理。
    private Set<Wife>wife=new HashSet<Wife>();
   @OneToMany
   @JoinColumn(name="getWife")
     public Set<Wife> getWife() {
        return wife;
    }

    @Id
     @GeneratedValue
    public int getId() {
        return id;
    }
    //q其餘get、set省略...
}

@Entity
public class Wife {
    private int id;
    private String name;
    @Id
    @GeneratedValue
    public int getId() {
        return id;
    }
    //q其餘get、set省略...
}

雙向關聯；

@Entity
public class Husband {
    private int id;
    private String name;
    private Set<Wife>wife=new HashSet<Wife>();//老婆太多了，放到set集合裏面方便管理。    
   @OneToMany(mappedBy="husband")
   @JoinColumn(name="getWife")
     public Set<Wife> getWife() {
        return wife;
    }
    @Id
     @GeneratedValue
    public int getId() {
        return id;
    }

}

@Entity
public class Wife {
    private int id;
    private String name;
    private Husband husband;
    @Id
    @GeneratedValue
    public int getId() {
        return id;
    }
   @ManyToOne
    public Husband getHusband() {
        return husband;
    }
}