Java Hibernate-如何删除nullable = false约束？

Question

我写的第一个版本为nullable = false;

@Entity
@Table(name = "ORGANIZATION")
@org.hibernate.annotations.Cache(usage = org.hibernate.annotations.CacheConcurrencyStrategy.READ_WRITE)
public class Organization extends AbstractEntity {
    @ManyToOne(fetch = FetchType.EAGER)
    @JoinColumn(nullable = false, name = "HOST_ID")
    private Host host;

然后我需要HOST_ID接受null值；

但是仅更改为nullable = true不会影响数据库表。

如何直接删除nullable = false约束而不访问数据库？