Problem

Runing the following Hibernate’s annotation sequence generator with PostgreSQL database.

        @Id	
	@Column(name="user_id", nullable=false)	
	@GeneratedValue(strategy = GenerationType.SEQUENCE ,generator="account_user_id_seq")
	private Integer userId;

Hits the following Unknown Id.generator exception.

Caused by: org.hibernate.AnnotationException: Unknown Id.generator: account_user_id_seq
	at org.hibernate.cfg.BinderHelper.makeIdGenerator(BinderHelper.java:413)
	at org.hibernate.cfg.AnnotationBinder.bindId(AnnotationBinder.java:1795)
	at org.hibernate.cfg.AnnotationBinder.processElementAnnotations(AnnotationBinder.java:1229)
	at org.hibernate.cfg.AnnotationBinder.bindClass(AnnotationBinder.java:733)

The sequence “account_user_id_seq” is created in PostgreSQL database, what caused the above exception?

Solution

When declaring the Hibernate’s annotation strategy to use “Sequences” as Id generator, try specify the @SequenceGenerator as well, as following

        @Id	
	@Column(name="user_id", nullable=false)	
	@SequenceGenerator(name="my_seq", sequenceName="account_user_id_seq")
	@GeneratedValue(strategy = GenerationType.SEQUENCE ,generator="my_seq")
	private Integer userId;
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