0
我在JPA单个表继承层次结构,如下所示子类不能坚持在超类中定义的关系:JPA /休眠单表继承 -
@Entity
@Inheritance(strategy = InheritanceType.SINGLE_TABLE)
@Table(catalog = "onedb", name = "content")
@DiscriminatorColumn(name = "oid_content_type", discriminatorType = DiscriminatorType.INTEGER)
public abstract class Content implements Serializable {
...
@OneToMany(cascade = CascadeType.PERSIST)
@JoinColumn(name = "oid_content", referencedColumnName = "oid_content")
private List<ContentKeyword> keywords;
...
@Entity
public abstract class RichMedia extends Content {
...
@OneToMany(mappedBy="richMedia", cascade =CascadeType.PERSIST)
private Set<RichMediaFile> richMediaFiles;
...
}
@Entity
@DiscriminatorValue("1")
public class RichMediaImage extends RichMedia {}
如可以看到的内容是最上面的基类,富媒体广告是RichMediaImage基类和内容具有定义如下ContentKeyword列表:
@Entity
@Table(catalog = "onedb", name="content_keyword")
public class ContentKeyword implements Serializable {
...
@ManyToOne
@JoinColumn(name = "oid_content")
private Content content;
}
我构建一个RichMediaImage并设置ContentKeyword它的列表,并尝试将持续整个对象。 的单个表,内容被插入与一个新行,并产生新的ID,但是当涉及到插入到未在SQL JPA提供此新ID的content_keyword表生成:
insert into onedb.content_keyword (oid_content, keyword) values (NULL, 'test')
投掷
MySQLIntegrityConstraintViolationException: Column 'oid_content' cannot be null
我非常感谢任何指针。
非常感谢您的快速响应,但我仍然得到确切的错误; oid_content不能为空。 – Cuneyt 2013-03-02 22:29:25
感谢Nizet,我在修复欢呼声中遇到了一个错误。非常感谢你的帮助 – Cuneyt 2013-03-02 22:42:08