PostgreSQL在JPA单表分层结构中的标识 [英] PostgreSQL identity in JPA single table hierarchy
问题描述
首先是我的环境：
$ b在一个Hibernate / JPA环境中使用PostgreSQL$ b
- PostgreSQL 8.3
- Spring 2.5.6SEC01
- Hibernate-entitymanager 3.4.0 .GA（从Glassfish更新工具安装）
- Hibernate-distribution 3.3.1.GA（从Glassfish更新工具安装）
- Glassfish V2
-
- Mac OS X 10.5.x
使用<$ c时遇到问题$ c> GenerationType IDENTITY 与单个表继承层次结构。
这里是我的两个实体：
$ b $ p Parent.java
<$ c $ b $ @ @Entity
@Inheritance（strategy = InheritanceType.SINGLE_TABLE）
@DiscriminatorColumn（name =generation，discriminatorType = DiscriminatorType.STRING）
@DiscriminatorValue（Parent）
public class Parent实现Serializable {
private static final long serialVersionUID = 1L;
私人长ID;
@Id
@GeneratedValue（strategy = GenerationType.IDENTITY）
public Long getId（）{
return id;
}
public void setId（Long id）{
this.id = id;
}
}
Child.java
@Entity
@DiscriminatorValue（Child）
public class Child extends Parent {
私人字符串babyName;
$ b $ **
* @return the babyName
* /
public String getBabyName（）{
return babyName;
$ b $ **
* @param babyName要设置的babyName
* /
public void setBabyName（String babyName）{
this.babyName = babyName;
DDL
create table父（生成varchar（31）不为空
，id bigserial不为空
，babyName varchar（255 ）
，主键（id）
）;
如果我尝试插入新的父项，则会收到错误消息：
org.postgresql.util.PSQLException：类型long的值不正确：父
我把日志记录到TRACE，这是输出：
TRACE TransactionSynchronizationManager - 限制值[org.springframework.orm.jpa.EntityManagerHolder@485e0366]键[com.sun.enterprise.util.EntityManagerFactoryWrapper@a6e312b]为线程[httpSSLWorkerThread-8080-0]
Hibernate：插入父（生成）值（'Parent'）
SQL错误：0，SQLState：22003
类型long的值不正确：父
TRACE TransactionInterceptor - 完成[com.xxx.yyy.service.MoveService.saveHuman ]异常后：javax.persistence.PersistenceException：org.hibernate.exception.DataException：无法插入：[com.xxx.yyy.temp.Parent]
TRACE RuleBasedTransactionAttribute - 应用规则来确定事务sh回滚javax.persistence.PersistenceException：org.hibernate.exception.DataException：无法插入：[com.xxx.yyy.temp.Parent]
如果我将标识符值更改为长分析的内容，例如 123 插入成功。不过，Hibernate似乎认为这个鉴别值是id。所以下面的代码：
父p = new Parent（）;
service.saveHuman（p）;
add（new Label（p，p id is+ p.getId（）））;
显示id为 123 ，而不是主键值为1。如果我将生成类型更改为 AUTO ，则会创建单个序列，并且插入似乎工作正常。如果我将它更改为 SEQUENCE ，并再次使用类级注释声明序列，它就可以工作。然而，根据我已阅读的文档，PostgreSQL支持这两种生成类型。
我也尝试了完全相同的代码，并用MySQL 5.0.51b转出数据库。这似乎运作良好。
那么这是我的代码，方言，Hibernate或PostgreSQL JDBC驱动程序中的错误？任何想法如何我可以缩小这个问题？任何人都可以重新产生这个问题，因为我试图搜索，还没有看到这个确切的问题。
注意：我也问过关于 Hibernate论坛的问题。当然我会反馈任何回应到这两个网站。
我只是从上面的注释中移植这个解决方案。 。使用版本8.3的PostgreSQL JDBC驱动程序： - ）。
I'm seeing strange behaviour when using PostgreSQL in a Hibernate/JPA environment with a single table inheritance hierarchy.
Firstly my environment:
- PostgreSQL 8.3
- Spring 2.5.6SEC01
- Hibernate-entitymanager 3.4.0.GA (installed from Glassfish update tool)
- Hibernate-distribution 3.3.1.GA (installed from Glassfish update tool)
- Glassfish V2
- Mac OS X 10.5.x
I'm having an issue when using a GenerationType of IDENTITY with a single table inheritance hierarchy.
Here are my two entities:
Parent.java
@Entity
@Inheritance(strategy=InheritanceType.SINGLE_TABLE)
@DiscriminatorColumn(name="generation", discriminatorType=DiscriminatorType.STRING)
@DiscriminatorValue("Parent")
public class Parent implements Serializable {
private static final long serialVersionUID = 1L;
private Long id;
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
public Long getId() {
return id;
}
public void setId(Long id) {
this.id = id;
}
}
Child.java
@Entity
@DiscriminatorValue("Child")
public class Child extends Parent {
private String babyName;
/**
* @return the babyName
*/
public String getBabyName() {
return babyName;
}
/**
* @param babyName the babyName to set
*/
public void setBabyName(String babyName) {
this.babyName = babyName;
}
}
DDL
create table Parent (generation varchar(31) not null
,id bigserial not null
,babyName varchar(255)
,primary key (id)
);
If I try to insert a new Parent I get an error:
org.postgresql.util.PSQLException: Bad value for type long : Parent
I turned up the logging to TRACE and this is the output:
TRACE TransactionSynchronizationManager - Bound value [org.springframework.orm.jpa.EntityManagerHolder@485e0366] for key [com.sun.enterprise.util.EntityManagerFactoryWrapper@a6e312b] to thread [httpSSLWorkerThread-8080-0]
Hibernate: insert into Parent (generation) values ('Parent')
SQL Error: 0, SQLState: 22003
Bad value for type long : Parent
TRACE TransactionInterceptor - Completing transaction for [com.xxx.yyy.service.MoveService.saveHuman] after exception: javax.persistence.PersistenceException: org.hibernate.exception.DataException: could not insert: [com.xxx.yyy.temp.Parent]
TRACE RuleBasedTransactionAttribute - Applying rules to determine whether transaction should rollback on javax.persistence.PersistenceException: org.hibernate.exception.DataException: could not insert: [com.xxx.yyy.temp.Parent]
If I change the discriminator value to be something that parses as a long e.g. 123 the insert succeeds. However Hibernate seems to think this discriminator value is the id. So the following code:
Parent p = new Parent();
service.saveHuman(p);
add(new Label("p", "p id is" + p.getId()));
Shows the id as 123 rather than the primary key value which is 1.
If I change the generation type to AUTO a single sequence is created and the insert seems to work ok. If I change it to SEQUENCE and declare the sequence with a class-level annotation again it works. However according to the documentation I have read PostgreSQL supports both generation types.
I also tried the exact same code and switched out the database with MySQL 5.0.51b. This seems to function fine.
So is this a bug in my code, the dialect, Hibernate, or the PostgreSQL JDBC driver? Any ideas how I can narrow down the problem? Anyone able to re-produce this issue as I have tried to search and haven't seen this exact problem yet.
Note: I've also asked the question on the Hibernate Forums. Naturally I will feedback any responses to both sites.
I'm just "porting" this solution from the comments above... use version 8.3 of the PostgreSQL JDBC driver :-).
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