生成的序列从1开始，而不是在注释中设置的1000 [英] Generated sequence starts with 1 instead of 1000 which is set in annotation

问题描述

我有这个注解 - 下面的代码 - 在我的实体类中，以便拥有个人合作伙伴表的序列。我期望序列以1000开头，因为我在部署期间使用import.sql将测试数据插入到我的数据库中，并且希望避免违反约束。但是当我想要保存数据比得到违反约束的异常时，它会通知我partner_id = 2已经存在的事实。它看起来像我错过了什么。

  @Id 
 @Column（name =partner_id）
 @SequenceGenerator（initialValue = 1000，
 allocationSize = 1，
 name =partner_sequence，
 sequenceName =partner_sequence）
 @GeneratedValue（generator =partner_sequence）
 private long partnerId; 
  

生成的序列如下所示：

  CREATE SEQUENCE partner_sequence 
 INCREMENT 1 
 MINVALUE 1 
 MAXVALUE 9223372036854775807 
 START 1 
 CACHE 1; 
 ALTER TABLE partner_sequence 
 OWNER TO postgres; 
  

我使用postgres 9.1。

我想念什么？这是我怎么接近我想要的？

感谢您提前提供任何帮助！

解决方案

initialValue 和 alocattionSize 特定于 hilo 使用序列的算法。根据此 initialValue 甚至不被支持。我甚至没有看到Java层如何支持它，因为序列值是在数据库中生成的。

另见 hibernate oracle序列产生较大鸿沟

I would like to ask some help regarding database sequence created by Hibernate.

I have this annotation - the code below - in my entity class in order to have individual sequence for partners table. I expect that the sequence starts with 1000, because I insert test data into my database using import.sql during deploy and I would like to avoid the constraint violation. But when I want to persist data than I got the constraint violation exception and it informs me about the fact the partner_id = 2 already exists. It looks like I missed something.

    @Id
    @Column(name = "partner_id")
    @SequenceGenerator(initialValue=1000, 
                        allocationSize=1,
                        name = "partner_sequence", 
                        sequenceName="partner_sequence")
    @GeneratedValue(generator="partner_sequence")
    private Long partnerId;

The generated sequence looks like this:

CREATE SEQUENCE partner_sequence
  INCREMENT 1
  MINVALUE 1
  MAXVALUE 9223372036854775807
  START 1
  CACHE 1;
ALTER TABLE partner_sequence
  OWNER TO postgres;

I use postgres 9.1.

Did I miss something? This is the way how can I approach what I want?

Thanks for any help in advance!

解决方案

initialValue and alocattionSize are specific to hilo algorithm that uses sequence. According to this initialValue is not even supported. I don't even see how it could be supported from Java layer since sequence values are generated in the database.

Also see hibernate oracle sequence produces large gap

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