Oracle APEX report - processing a field value - sql

Question

I have been creating Oracle APEX reports for a while.
I need to processes a column value to charge it's format.
The current SQL looks like this. All is good.
select PP_RUNDATA.ID as ID,
PP_RUNDATA.PP_START_TIME as PP_START_TIME,
PP_RUNDATA.PP_END_TIME as PP_END_TIME,
from PP_RUNDATA PP_RUNDATA
The time columns are in seconds. This PL/SQL converts the seconds into date / time. (this work well)
alter session set nls_date_format="dd/mm/yyyy - hh24:mi:ss";
select date '1970-01-01' + 1661596871 * interval '1' second result from dual;
I need to bring together the SQL and PL/SQL and change the 1661596871 to the column value.
I know I can use a "List Value" to process the PP_START_TIME / PP_END_TIME column using PL/SQL returning SQL.
A very poor, not working example,
declare
temp1 varchar2(500);
begin
EXECUTE IMMEDIATE 'alter session set nls_date_format="dd/mm/yyyy - hh24:mi:ss"';
select date '1970-01-01' + PP_START_TIME * interval '1' second into temp1 from dual;
return 'select temp2 from dual';
End;
I know there are more than two things wrong with this coding;
1) Syntax to access data in column PP_START_TIME (maybe &PP_START_TIME.)
2) the "return statement"
What am I doing wrong in the coding / my thinking in the above or maybe the overall approach in Oracle APEX Reports?
Thanks for looking
Pete

Answer 1

You can use:
select ID,
DATE '1970-01-01' + PP_START_TIME * INTERVAL '1' SECOND as PP_START_TIME,
DATE '1970-01-01' + PP_END_TIME * INTERVAL '1' SECOND as PP_END_TIME
from PP_RUNDATA
If you want a particular format then you can use TO_CHAR:
select ID,
TO_CHAR(
DATE '1970-01-01' + PP_START_TIME * INTERVAL '1' SECOND,
'dd/mm/yyyy - hh24:mi:ss'
) as PP_START_TIME,
TO_CHAR(
DATE '1970-01-01' + PP_END_TIME * INTERVAL '1' SECOND,
'dd/mm/yyyy - hh24:mi:ss'
) as PP_END_TIME
from PP_RUNDATA