我尝试用Hibernate 5.2实现单一表继承。 基类Hibernate继承与SingleTable
@Entity
@Inheritance(strategy=InheritanceType.SINGLE_TABLE)
@DiscriminatorColumn(name="type", discriminatorType= DiscriminatorType.STRING)
@DiscriminatorValue("HAKSAHIBI")
@DiscriminatorOptions(force=true)
public class PropertyOwner implements implements Serializable{
@Id
@GeneratedValue(strategy=GenerationType.IDENTITY)
long id;
@ManyToOne
Property property;
@ManyToOne
Person person;
}
作者类扩展PropertyOwner:
@Entity
@DiscriminatorValue("AUTHOR")
class Author extends PropertyOwner {
}
作曲类扩展PropertyOwner:
@Entity
@DiscriminatorValue("COMPOSER")
class Composer extends PropertyOwner {
}
Person类:
public class Person {
@Id
@GeneratedValue(strategy=GenerationType.IDENTITY)
long id;
String title;
}
物业CLA SS
public class Property{
@Id
@GeneratedValue(strategy=GenerationType.IDENTITY)
long id;
String title;
@OneToMany
Set<Composer> composers = new HashSet<Composer>();
@OneToMany
Set<Author> authors = new HashSet<Author>();
}
我期待的表结构如下:
CREATE TABLE `Property` (
`id` bigint(20) NOT NULL,
`title` varchar(255) DEFAULT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1;
CREATE TABLE `Person` (
`id` bigint(20) NOT NULL AUTO_INCREMENT,
`title` varchar(255) DEFAULT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1;
CREATE TABLE `PropertyOwner` (
`type` varchar(31) NOT NULL,
`id` bigint(20) NOT NULL AUTO_INCREMENT,
`property_id` bigint(20) DEFAULT NULL,
`person_id` bigint(20) DEFAULT NULL,
PRIMARY KEY (`id`),
KEY `FK77apjkkl14xwe45rs1ocgtt4u` (`property_id`),
KEY `FKqagfofgupovfly26enivfhm3j` (`person_id`),
CONSTRAINT `FK77apjkkl14xwe45rs1ocgtt4u` FOREIGN KEY (`property_id`) REFERENCES `property` (`id`),
CONSTRAINT `FKqagfofgupovfly26enivfhm3j` FOREIGN KEY (`person_id`) REFERENCES `person` (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1;
但遗憾的是作者和作曲班,下面的语句
CREATE TABLE `property_propertyOwner` (
`Property_id` bigint(20) NOT NULL,
`author_id` bigint(20) NOT NULL,
`composer_id` bigint(20) NOT NULL,
UNIQUE KEY `UK_rv9fxc06rcydqp6dqpqbmrkie` (`author_id`),
UNIQUE KEY `UK_fm4v55i021l5smuees0vs3qmy` (`composer_id`),
KEY `FKt3yqcltkd0et8bj08ge0sgrqb` (`Property_id`),
CONSTRAINT `FK1pj2606cjxrb70ps89v7609hg` FOREIGN KEY (`author_id`) REFERENCES `PropertyOwner` (`id`),
CONSTRAINT `FKfdh3r95jffvd07u3xn21824r7` FOREIGN KEY (`composer_id`) REFERENCES `PropertyOwner` (`id`),
CONSTRAINT `FKt3yqcltkd0et8bj08ge0sgrqb` FOREIGN KEY (`Property_id`) REFERENCES `Property` (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1;
什么,我做错了创建另一个表?我期望不应该创建property_PropertyOwner表,Author,Composer类信息应该保存在propertyOwner表中。
注意:我尝试了Enumarated注解,但是这次在Property类中我无法定义Setauthor字段,我必须定义Set并将枚举信息添加到该对象。 在此先感谢。
好像你在映射中缺少'mappedBy'。使用'@OneToMany(mappedBy =“property”)''和'@OneToMany(mappedBy =“person”)' –