Can I request the next value of a sequence via Java?

[Radenixlol]

Hello, I wanted to know if there is a way to request the value of a sequence through a query, since I tried "values nextval for name_seq" as I would do through the interface and it does not recover the value, and the documentation only mentions methods to embed it within an INSERT, and I have a use case in which I need to bring the value to my program to do something with it beforehand.

[wimjongman]

Can you provide a code snippet that explains your problem better?

[Radenixlol]

String sql = "values nextval for ORDER_SEQ"
Query query = em.createNativeQuery(sql);
query.getFirstResult();

I just want to retrieve the next value in the sequence

and I only find examples like this in the IBM documentation:

INSERT INTO ORDERS (ORDERNO, CUSTNO)
VALUES (NEXT VALUE FOR ORDER_SEQ, 12)

which doesn't work for me

Note: ORDER_SEQ is de name of sequence

[Radenixlol]

I would also like to know if there is a query in SQL that allows me to verify the existence of a sequence in the system. I have not found any way to do so other than through the database itself.

[wimjongman]

1. When you ask for the next sequence it automatically increments
2. The sequence is implemented as a data area in the schema

Create the sequence

set schema mylib

CREATE SEQUENCE ORDER_SEQ    
START WITH 500               
INCREMENT BY 1               
MAXVALUE 10000               
NOCYCLE                      
CACHE 24      

Increment the sequence

select (next value for order_seq) from qcllesrc limit 1 -- any table

Get the last used increment

select (previous value for order_seq) from qcllesrc limit 1 -- any table

[Radenixlol]

@wimjongman Thank you very much

Another question, do you know where IBM I keeps track of this sequence? Is there a table that can be consulted?

[wimjongman]

2. The sequence is implemented as a data area in the schema

[Radenixlol]

I guess it's not queryable via SQL then, I've been doing this for a short time and I'm really not sure what implications a data area has with respect to a file, thank you very much anyway

[wimjongman]

Sorry, you can get it though the https://www.ibm.com/docs/en/i/7.5?topic=services-object-statistics-table-function