JPA Spring Boot postgresql : Insert data with the last ID

Question

I have a MyClass entity with an auto increment id at the time of the project deployment I have an init.sql file to initialize the MY_CLASS table by adding two lines the problem when I use my web service REST to insert a new line in the MY_CLASS table I have an error message of duplicate key of id 1 for the first click and id 2 on the second click but after the POST goes without problems. To solve this problem I can add the following line in my init.sql file

ALTER SEQUENCE MY_CLASS_id_seq RESTART WITH 3;

My question: How can I configure my POST to persist the data with the last id because whenever I can insert data with SQL.

@Entity
@Cacheable
@Getter
@Setter
@Table(name = "MY_CLASS")
public class MyClass {
 @Id
 @GeneratedValue(strategy = GenerationType.IDENTITY)
 private Long id;
 @NotNull
 private String label;
}
@RepositoryRestResource(collectionResourceRel = "clazz", path = "clazz")
public interface MyClassRepository extends PagingAndSortingRepository<MyClass, Long> {
}

init.sql

INSERT INTO public.MY_CLASS (label) values('label_1');
INSERT INTO public.MY_CLASS (label) values('label_2');

Answer 1

Wouldn't you use the sequence generator, would you?

public class MyClass {
 public static final String SEQUENCE_NAME = "MY_CLASS_id_seq";
 @Id
 @GeneratedValue(strategy = SEQUENCE, generator = SEQUENCE_NAME)
 @SequenceGenerator(name = SEQUENCE_NAME, sequenceName = SEQUENCE_NAME)
 private Long id;
 @NotNull
 private String label;
}

• Dali: your proposal solved my problem just the id jumped to 50 instead of using the last id 3. i do not understand why 50 and if i initialize my database with 50 lines in init.sql file would not ask problem
• Andriy Slobodyanyk: When Hibernate uses sequence generator it doesn't fetch the sequence value every time. Instead of it grabs a number of ids (50 by default) and manages them itself. Anyway you shouldn't worry if every number of sequence is used and there are gaps between them.