How is the hibernate_sequence Table Generated in Hibernate?

What are the steps involved in the generation of the hibernate_sequence table in Hibernate?

// Example of using Hibernate's sequence generator in an entity class
@Entity
public class MyEntity {
   @Id
   @GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "my_seq_gen")
   @SequenceGenerator(name = "my_seq_gen", sequenceName = "hibernate_sequence")
   private Long id;
   // other fields and methods
}

The hibernate_sequence table in Hibernate is primarily used to generate unique primary key values for entities using sequences. This provides a reliable and efficient way to handle IDs, especially in clustered environments.

@Entity
public class Product {
   @Id
   @GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "prod_seq")
   @SequenceGenerator(name = "prod_seq", sequenceName = "hibernate_sequence")
   private Long productId;
   private String productName;
}

Causes

• The use of a sequence generation strategy in your entity class.
• The Hibernate configuration set to automatically generate the schema on startup, which includes the sequence definition.

Solutions

• Ensure that your Hibernate configuration is set to manage schema updates effectively.
• If you want to customize the sequence generation, define your own sequence generator with the @SequenceGenerator annotation.

Mistake: Not defining a sequence generator leading to default behavior that may not meet your needs.

Solution: Always define a specific sequence generator when your business logic requires specific ID handling.

Mistake: Setting the Hibernate configuration to not auto-update the schema may cause the hibernate_sequence table to not be created.

Solution: Ensure that the 'hibernate.hbm2ddl.auto' property is set to 'update' or 'create'.