What are the different types of identifier generation?

Answer

Following are the types of id generation strategy required to specify with @GeneratedValue annotation: -

• Automatic Id generation - In this case, the application doesn't care about the kind of id generation and hand over this task to the provider. If any value is not specified explicitly, the generation type defaults to auto.
• Id generation using a table - The identifiers can also be generated using a database table.
• Id generation using a database sequence - Databases support an internal mechanism for id generation called sequences. To customize the database sequence name, we can use the JPA @SequenceGenerator annotation.
• Id generation using a database identity - In this approach, whenever a row is inserted into the table, a unique identifier is assigned to the identity column that can be used to generate the identifiers for the objects.