JPA复合主键和jointable具有独特的键
问题描述:
这里的SQL表:
选择主键是名称+值
JPA复合主键和jointable具有独特的键
CREATE TABLE `option` (
id int(11) NOT NULL AUTO_INCREMENT,
`name` varchar(45) NOT NULL,
`value` varchar(45) NOT NULL,
PRIMARY KEY (`name`, `value`),
UNIQUE KEY `id_UNIQUE` (`id`)
)
产品主键是增量编号
CREATE TABLE `product` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`name` varchar(50) NOT NULL,
PRIMARY KEY (`id`)
)
一产品有几个选项(参考唯一密钥“id”)
CREATE TABLE product_option (
`id` int(11) NOT NULL AUTO_INCREMENT,
`id_product` int(11) NOT NULL,
`id_option` int(11) NOT NULL,
PRIMARY KEY (`id`),
KEY `id_product` (`id_product`),
KEY `id_option` (`id_option`),
CONSTRAINT `FK_product_option` FOREIGN KEY (`id_product`) REFERENCES `product` (`id`) ON DELETE NO ACTION ON UPDATE NO ACTION,
CONSTRAINT `FK_option_product` FOREIGN KEY (`id_option`) REFERENCES `option` (`id`) ON DELETE NO ACTION ON UPDATE NO ACTION
)
在Java方面,我已经映射 “选项” 这样
@Embeddable
public class OptionId implements Serializable{
@Column(name="value")
private String value;
@Column(name="name")
private String name;
}
@Entity @Table(name="option")
public class Option {
@Column(name="id", unique=true)
@GeneratedValue(strategy=GenerationType.IDENTITY)
private Long id;
@EmbeddedId
private OptionId primaryKey;
public OptionId getPrimaryKey() {
return primaryKey;
}
public void setPrimaryKey(OptionId primaryKey) {
this.primaryKey = primaryKey;
}
}
和产品这样
@Entity
@Table(name="product")
public class Product {
@Id @Column(name="id")
@GeneratedValue(strategy=GenerationType.IDENTITY)
private Long id;
@Column(name="name")
private String name
@OneToMany(cascade=CascadeType.ALL, fetch=FetchType.LAZY)
@JoinTable(
name="product_option",
joinColumns = @JoinColumn(name="id_product"),
inverseJoinColumns = @JoinColumn(name="id_option", referencedColumnName="id")
)
private Set<Option> options;
}
然后在执行时,我得到这个错误
Caused by: java.lang.ArrayIndexOutOfBoundsException: 1
at org.hibernate.sql.SelectFragment.addColumns(SelectFragment.java:107)
at org.hibernate.persister.collection.BasicCollectionPersister.manyToManySelectFragment(BasicCollectionPersister.java:308)
at org.hibernate.persister.collection.BasicCollectionPersister.selectFragment(BasicCollectionPersister.java:294)
at org.hibernate.loader.JoinWalker.selectString(JoinWalker.java:1070)
at org.hibernate.loader.AbstractEntityJoinWalker.initStatementString(AbstractEntityJoinWalker.java:124)
at org.hibernate.loader.AbstractEntityJoinWalker.initStatementString(AbstractEntityJoinWalker.java:109)
at org.hibernate.loader.AbstractEntityJoinWalker.initAll(AbstractEntityJoinWalker.java:91)
at org.hibernate.loader.AbstractEntityJoinWalker.initAll(AbstractEntityJoinWalker.java:78)
at org.hibernate.loader.entity.CascadeEntityJoinWalker.<init>(CascadeEntityJoinWalker.java:52)
at org.hibernate.loader.entity.CascadeEntityLoader.<init>(CascadeEntityLoader.java:47)
at org.hibernate.persister.entity.AbstractEntityPersister.createLoaders(AbstractEntityPersister.java:3254)
at org.hibernate.persister.entity.AbstractEntityPersister.postInstantiate(AbstractEntityPersister.java:3191)
at org.hibernate.persister.entity.SingleTableEntityPersister.postInstantiate(SingleTableEntityPersister.java:728)
at org.hibernate.impl.SessionFactoryImpl.<init>(SessionFactoryImpl.java:348)
at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1872)
at org.hibernate.ejb.Ejb3Configuration.buildEntityManagerFactory(Ejb3Configuration.java:906)
at org.hibernate.ejb.HibernatePersistence.createContainerEntityManagerFactory(HibernatePersistence.java:74)
at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.createNativeEntityManagerFactory(LocalContainerEntityManagerFactoryBean.java:225)
at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.afterPropertiesSet(AbstractEntityManagerFactoryBean.java:308)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1477)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1417)
... 60 more
如果我删除“referencedColumnName”,当然我得到错误
A Foreign key refering Option from Product has the wrong number of column. should be 2
但我不知道如何解决这个问题
答
根据你的模式,你的实体注释稍微偏离。当你指定“产品”和“选项”,你应该使用“id_product”和“id_option”:
@OneToMany(cascade=CascadeType.ALL, fetch=FetchType.LAZY)
@JoinTable(
name="product_option",
joinColumns = @JoinColumn(name="id_product"),
inverseJoinColumns = @JoinColumn(name="id_option", referencedColumnName="id")
)
private Set<Option> options;
顺便说一句,你的生活会容易得多,从长远来看,如果切换主并在您的选件表上提供独特的按键。
我的错误。我纠正了错字。 (我仍然有问题)。出于商业目的,最好有一个有意义的主键,并使用技术ID仅用于数据库目的 – user1800633
正确,但在数据库级别,您应该处理'技术'ID。你独特的钥匙成为你的'商业钥匙'。我会在今天晚些时候开始工作。它看起来应该按原样运行。 – Perception