JPA save() can't get the last ID from an existing table

Question

When I save a new entity, it's Primary Key ID started saving from 1, as supposed to. But there were rows on the table before I implemented the JPA.

Entity.class:

    @Data
    @Entity
    @NoArgsConstructor
    @AllArgsConstructor
    @Table(schema = "db", name = "table")
    public class Entity {
        
        @Id
        @GeneratedValue(strategy = GenerationType.IDENTITY)
        @Column(name = "id", updatable = false, nullable = false)
        private Long id;
    }

Example: Let's say there are 10 rows. I .save() a new entity and it saves with the id = 5 , and of course I get an exception.

Do I need to keep saving until the generated ID gives a + 10 number. Is this normal? Can't the @GeneratedValue get the last id from the table and +1 itself?

Answer 1

The issue was with the autogenerated ID. As I did have rows on the table before implementing the JPA, the auto increment started with 1.

Fixed by modifying the auto increment sequence:

SELECT SETVAL('table_id_seq', (SELECT MAX(id) + 1 FROM table));