db2 native SQL stored procedure

I am learning and new to db2.

Here is what I am trying to achieve in steps:

Step 1: create a stored procedure to insert data into the table, once inserted
Step 2: run select on the same table, get the values and paste them on the screen/output.

Step 1 is complete and able to insert data into the table. Now I need help with executing the select statement and print the result.. I am trying to put this select statement in the same stored procedure after the insert...

execute stored procedure
insert into the table
wait for 1 second
select the data from the same table it inserted.
(bit of logic) here

Query:

select  
    columna, columnb, columnc 
from 
    table A 
when 
    columnd <> null, 

if columnd is null then 
    select the columna, columnb, columnc 
    from table A 
    where max(columne)

Here both columnd and columne are timestamp columns and need the latest row from the table.

Like fetch first 1 row only in both the cases.

Once the results are selected columna, columnb, columnc should be printed as output once the stored procedure is completed.

TIA..

I have tried something like this below:

putting the whole second step in second stored procedure and calling the stored procedure inside the main insert stored procedure. But I am failing in the logic. As I said - I am still learning...

CREATE PROCEDURE test()
LANGUAGE SQL
BEGIN 
        DECLARE V_COLUMNA VARCHAR(255);

DECLARE V_COLUMNB VARCHAR(255);

DECLARE V_COLUMNC VARCHAR(255);

DECLARE V_COLUMND VARCHAR(255);

DECLARE V_COLUMNE VARCHAR(255);

IF (
SELECT
    COUNT(*)
FROM
    tableA pl
WHERE
    columnd IS NULL) > 0 THEN 
        
            SELECT
    columna,
    columnb,
    columnc,
    columne
            INTO
    V_COLUMNA,
    V_COLUMNB,
    V_COLUMN,
    V_COLUMNE
FROM
    tableA
ORDER BY
    TIMESTAMP DESC 
            FETCH FIRST 1 ROW ONLY;
ELSE 
        
            SELECT
    columna,
    columnb,
    columnc,
    columnd
            INTO
    V_COLUMNA,
    V_COLUMNB,
    V_COLUMN,
    V_COLUMND
FROM
    tableA
ORDER BY
    TIMESTAMP DESC 
            FETCH FIRST 1 ROW ONLY;
END IF;

IF V_COLUMND IS NOT NULL THEN
SELECT
    V_COLUMNA,
    V_COLUMNB,
    V_COLUMN,
    V_COLUMND;
END IF;

IF V_COLUMND IS NULL THEN
SELECT
    V_COLUMNA,
    V_COLUMNB,
    V_COLUMN,
    V_COLUMNE;
END IF;
END;

Solution

You can alter Your DB2 procedure for output in this way:

CREATE OR REPLACE PROCEDURE
...
SPECIFIC ...
DYNAMIC RESULT SETS 1
...
BEGIN
  ...
  IF ... THEN
    BEGIN
      DECLARE cur1 CURSOR WITH RETURN TO CALLER FOR
        SELECT ...
        ...
        ;
      OPEN cur1;
    END;
  END IF;
END @