一个带有 PostgreSQL 的实体的多个 Hibernate 序列生成器

问题描述

我可以为一个实体使用多个序列生成器吗，比如

Can I use Multiple sequence generators for one entity, like

@Id
@SequenceGenerator(name="subscription_id_seq",sequenceName="subscription_id_seq", allocationSize=7)
@GeneratedValue(strategy=GenerationType.SEQUENCE, generator="subscription_id_seq")
@Column(unique=true, nullable=false)
private Integer id

@Column(name="code", nullable=false, unique=true )
@SequenceGenerator(name="subscription_code_1_seq",sequenceName="subscription_code_1_seq", allocationSize=7)
@GeneratedValue(strategy=GenerationType.SEQUENCE, generator="subscription_code_1_seq")
private Integer code;

推荐答案

不，你不能.生成器仅适用于标识符列.

No you can not. The generator are applicable for identifier columns only.

确保您使用脚本(例如 hibernate.hbm2ddl.import_files)创建此序列:

Make sure you create this sequence with a script (e.g. hibernate.hbm2ddl.import_files):

create sequence subscription_code_1_seq start 1 increment 7

然后使用这样的映射:

@Id
@SequenceGenerator(
        name="subscription_id_seq",
        sequenceName="subscription_id_seq",
        allocationSize=7
)
@GeneratedValue(
        strategy=GenerationType.SEQUENCE,
        generator="subscription_id_seq"
)
@Column(unique=true, nullable=false)
private Integer id;

@Column(
        name="code",
        nullable=false,
        unique=true,
        insertable = false,
        updatable = false,
        columnDefinition = "BIGINT DEFAULT nextval('subscription_code_1_seq')"
)
@Generated(GenerationTime.INSERT)
private Integer code;

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