休眠和Oracle序列 [英] Hibernate and Oracle Sequence

问题描述

我有一个Oracle序列和Hibernate的问题。我使用这段代码来获取带有hibernate的Oracle序列

  @Id 
 @GeneratedValue（strategy = GenerationType.SEQUENCE，generator =student_id_seq）
 @SequenceGenerator（name =student_id_seq，sequenceName =Student_seq）
 @Column（name =StudentID）
 public Long getStudentId（）{
返回this.studentId; 
} 
 
 public void setStudentId（Long studentId）{
 this.studentId = studentId; 
} 
  

但是当我向表中插入新值时，生成的值不正确。例如：
当我在数据库中有两个记录时，id为2和3，当我插入新的记录时，它的id不是4但是是25.我不知道该怎么做。

解决方案

您应该将 allocationSize 设置为 1
$ $ p $ code $ @ student_id_seq，
sequenceName =Student_seq，
allocationSize = 1）


您可以阅读文档 SequenceGenerator文档

I have a problem with Oracle sequence and Hibernate. I used this code to get Oracle Sequence with hibernate

@Id
@GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "student_id_seq")
@SequenceGenerator(name = "student_id_seq", sequenceName = "Student_seq")
@Column(name = "StudentID")
public Long getStudentId() {
    return this.studentId;
}

public void setStudentId(Long studentId) {
    this.studentId = studentId;
}

but when i insert a new value to the table, the generated value is incorrect. For example: when I had two records in database with id 2 and 3, and when I inserted new one, it's id was not 4 but 25. I have no idea what to do with it.

解决方案

You should set allocationSize to 1

@GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "student_id_seq")
@SequenceGenerator(name = "student_id_seq", 
                   sequenceName = "Student_seq",
                   allocationSize = 1)  

You can read more in documentation SequenceGenerator doc

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