hibernate @Id @GeneratedValue with non auto-increment and i dont have sequence

Question

i have situation on which i try to persist entity with id that depends on the max id value, for example the new entity id will be MAX(id)+1. now i try to use JPA to persist this entity

@Entity
@Table(name = "product")
public class ProductDetails {

    @Id
    @GeneratedValue
    private String id;

i used strategy = GenerationType.AUTO, strategy = GenerationType.IDENTITY,strategy = GenerationType.SEQUENCE,strategy = GenerationType.TABLE none of them work, so i think i can solve it through selecting the max id then +1 and use that value (i did not try it) what i am asking for, is there is any way to handle this situation through JPA or Hibernate.Note:the id columns is not auto-increment and the db doesn't have sequence.

it doesn't work because its a String. if you use a Long, the `GenerationType.AUTO` should work fine. https://stackoverflow.com/questions/10100970/how-to-generate-a-hibernate-id-with-auto-generate-with-a-starting-value — XtremeBaumer, Jun 01 '17 at 12:22
Maybe this one https://stackoverflow.com/questions/18622716/how-to-use-id-with-string-type-in-jpa-hibernate — Emil Hotkowski, Jun 01 '17 at 12:33

score 1 · Answer 1 · answered Jun 01 '17 at 12:35

1

Don't use String as Primary key. if you need id like "ABC123" then take 2 id columns. One as id(int) PK, second as display_id(String). You can auto-generate display_id in database level using trigger.

answered Jun 01 '17 at 12:35

Biraj Sahoo

44
5

Please understand the issue. How can you get Max(id) if you will take id as String ? – Biraj Sahoo Jun 01 '17 at 13:32
i understand the issue, i don't want use Max(id), that is how the SQL is written by another one. i try to figure out solution.i already made the Id as long and strategy = GenerationType.AUTO, did not work – Melad Basilius Jun 01 '17 at 14:26

score 1 · Answer 2 · answered Jun 01 '17 at 13:30

If you use String as a type of your Id you shouldn't use auto-increment cause String is something that can't be incremented since it's not a number type. Just leave @Idand add @GeneratedValue(generator = "uuid") - that should work. Additionally you can add @GenericGenerator(name = "uuid", strategy = "uuid2")

hibernate @Id @GeneratedValue with non auto-increment and i dont have sequence

2 Answers2