spring boot id auto generated

  1. Entity Class with ID Field:java @Entity public class YourEntity { @Id @GeneratedValue(strategy = GenerationType.IDENTITY) private Long id; // other fields and methods }

  2. @Entity Annotation:

  3. Indicates that the class is a JPA entity.

  4. Represents a table in the database.

  5. @Id Annotation:

  6. Marks the field as the primary key of the entity.

  7. Denotes the unique identifier for each record in the database table.

  8. @GeneratedValue Annotation:

  9. Specifies the generation strategy for the values of the primary key.

  10. Here, GenerationType.IDENTITY is used, indicating that the database should automatically assign a unique value for the primary key.

  11. Long id Field:

  12. Represents the primary key of the entity.

  13. Type Long is used for the primary key.

  14. Database Table:

  15. The entity class, when processed by JPA, corresponds to a table in the database.

  16. The table has a column for each field in the entity, including the automatically generated ID column.

  17. Automatic ID Generation:

  18. The @GeneratedValue annotation with GenerationType.IDENTITY strategy ensures that the ID is automatically generated by the database.

  19. This is particularly useful for simplifying the process of creating new records without manually assigning IDs.

  20. Persistence Context:

  21. When an entity is managed by the EntityManager (part of JPA), changes to its state are tracked.

  22. The automatic ID generation allows for easy management of entity instances within the persistence context.

  23. Database Schema:

  24. The presence of the ID field with the specified annotations influences the creation of the database schema.
  25. The schema includes information about the table structure, primary key, and auto-incrementing property for the ID column.