Hibernate + oracle序列+触发器 [英] Hibernate + oracle sequence + trigger

问题描述

我有一个索引自动填充的表，其中有一个使用序列（Oracle数据库）的触发器

  CREATE TABLE A 
（
 IDS NUMBER（10）NOT NULL 
）
 
 
创建或替换触发器A_TRG 
插入前
 ON A参考新的旧OLD AS旧
每行
 BEGIN 
：new.IDS：= A_SEQ.nextval; 
 END A_TRG; 
 / 
  

我有一个匹配的Java类：

 类A {
 @Id 
 @SequenceGenerator（name =aSequence，sequenceName =A_SEQ，allocationSize = 1）
 @GeneratedValue（generator =aSequence，strategy = GenerationType.SEQUENCE）
 @Column（name =IDS）
 Long id; 
 
 ... 
} 
  

当我尝试坚持一个像这样的实例：
$ b $ pre $ EntityTransaction transaction = entityManager.getTransaction（）;
transaction.begin（）;
A a = new A（）;
Long id = getHibernateTemplate（）。save（a）;
transaction.commit（）;


我遇到这个问题：

• save调用返回的代码中的ID = X

X + 1

有没有办法设置Hibernate来让数据库触发器创建ID？

谢谢 解决方案

使用Oracle触发器从序列中生成id的HIbernate问题

我必须调整我的触发器才能在没有ID的情况下运行：

<$ p $创建或替换触发器A_TRG
插入前
参考新的新旧OLD旧
每行
当（New.IDS为空时） - （1）
BEGIN
：new.IDS：= A_SEQ.nextval;
END A_TRG; （1）此行允许Hibernate手动调用A_SEQ.nextVal来设置ID，然后绕过触发器，否则Hibernate将无用地获得nextval，因为触发器会再次重置ID调用nextval。

I have a table with an index auto filled by a trigger that use a sequence (Oracle database)

CREATE TABLE A
(
  IDS                           NUMBER(10)      NOT NULL
)


CREATE OR REPLACE TRIGGER A_TRG
BEFORE INSERT
ON A REFERENCING NEW AS New OLD AS Old
FOR EACH ROW
BEGIN
  :new.IDS := A_SEQ.nextval;
END A_TRG;
/

I have a matching Java class:

Class A {
   @Id
   @SequenceGenerator(name = "aSequence", sequenceName = "A_SEQ", allocationSize = 1)
   @GeneratedValue(generator = "aSequence", strategy = GenerationType.SEQUENCE)
   @Column(name = "IDS")
   Long id;

   ...
}

When I try to persist an instance of A like this:

EntityTransaction transaction = entityManager.getTransaction();
transaction.begin();
A a = new A();
Long id = getHibernateTemplate().save(a);
transaction.commit();

I get this problem:

• ID in code returned by the save call = "X"

• ID in database = "X+1"

Is there a way to setup Hibernate to let the database trigger create the ID ?

Thanks

解决方案

Reponse found at HIbernate issue with Oracle Trigger for generating id from a sequence

I need to adapt my trigger to run only if no ID is given:

CREATE OR REPLACE TRIGGER A_TRG
BEFORE INSERT
ON A REFERENCING NEW AS New OLD AS Old
FOR EACH ROW
WHEN (New.IDS is null) -- (1)
BEGIN
  :new.IDS := A_SEQ.nextval;
END A_TRG;
/

(1) this line allow Hibernate to manually call A_SEQ.nextVal to set the ID and then bypass the trigger else Hibernate will get the nextval for uselessly because the trigger will always reset the ID calling nextval again

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