Hi,

I have to include startweek and endweek validation in an oracle form. Here, startweek and endweek includes year and a week number like '201801'.
Whenever user enters a startweek or endweek value beyond the allowed range then I have to throw an error.
Which means for a given year that user enters, I have to find the range of startweek and endweek.
Also, there is no custom table that has year data beyond 2019.
I have just joined an IT company as a fresher. Please, provide an answer that can help me solve the issue.

Here, I am trying to write a code that gives weeks in a given year

SET SERVEROUTPUT ON;
declare
L_YEAR number;
L_DATE date;
FIRST_DAY date;
LAST_DAY date;
week char(10);
begin
L_YEAR:=2019; ------this value will be taken from user via an oracle form
L_DATE:=TO_DATE('01-JAN-'||L_YEAR,'DD-MM-YYYY');
select TRUNC (L_DATE, 'YEAR') into FIRST_DAY from DUAL;----first day of a year-----
select ADD_MONTHS(TRUNC (L_DATE ,'YEAR'),12)-1 into last_day from DUAL;-------last day of an year -----
DBMS_OUTPUT.PUT_LINE(FIRST_DAY||' '||LAST_DAY);
select to_char(last_day,'iw') into WEEK from DUAL;------this gives min week(i.e startweek information. I hoped it to give endweek information....
DBMS_OUTPUT.PUT_LINE(week);
end;

SQL> set serverout on
SQL> declare
  2    l_year int := 2019;
  3    l_date date;
  4  begin
  5    l_date := trunc(to_date(to_char(l_year+1),'YYYY'),'YYYY')-1;
  6    while to_char(l_date,'IW') = '01'
  7    loop
  8      l_date := l_date - 1;
  9    end loop;
 10    dbms_output.put_line(l_date||': Week'||to_char(l_date,'IW'));
 11  end;
 12  /
29-DEC-19: Week52

PL/SQL procedure successfully completed.