Hibernate 实体中的多个 SequenceGenerator

Question

是否可以在 Hibernate Entity 中使用 2 个序列生成器 Class。我想为我的案例使用两个序列生成器，一个用于主键，另一个用于简单字段。我怎样才能达到同样的效果？

@Data
@Table(name="a_b")
@SequenceGenerator(name = "a1_seq", sequenceName = "a1_seq", allocationSize    = 1)
@SequenceGenerator(name = "b1_seq", sequenceName = "b1_seq", allocationSize = 1)
public class ABC {

    @Id
    @Column(name = "id")
    @GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "a1_seq")
    private Integer id;

    @Column(name = "c")
    private String c;

    @GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "b1")
    @Column(name = "b)
    private Integer b;

}

Answer 1

在列级别而不是 class 级别定义您的@SequenceGenerator。因此，您可以为两个不同的列创建两个单独的 sequenceGenerator - a1_seq 和 b1。

@Data
@Table(name="a_b")

public class ABC {

  @Id
  @Column(name = "id")
  @SequenceGenerator(name = "a1_seq", sequenceName = "a1_seq", allocationSize    = 1)
  @GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "a1_seq")
  private Integer id;

  @Column(name = "c")
  private String c;

  @SequenceGenerator(name = "b1_seq", sequenceName = "b1_seq", allocationSize = 1)
  @GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "b1")
  @Column(name = "b)
  private Integer b;

}

这应该有效。我还没有测试过它，但由于在现场级别允许使用 SequenceGenerator，它应该可以工作。

Answer 2

你应该只有一个 SequenceGenerator 作为主键：

@Id
@Column(name = "id")
@SequenceGenerator(name = "a1_seq", sequenceName = "a1_seq", allocationSize    = 1)
@GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "a1_seq")
private Integer id;

对于外键，您可以：

@Column(name = "b, columnDefinition="serial")
private Integer b;

这应该适用于 PostgreSQL。

Hibernate 实体中的多个 SequenceGenerator

Multiple SequenceGenerator in Hibernate Entity

java

hibernate

jpa

orm

hibernate-mapping