PL/SQL procedure to output line the given date if not existing, latest date should be given

Question

I have this table informationvalues with the contents:

Now I create a procedure where I need to input a date parameter which should output line the correct attr with given price. If the date doesn't exist the latest date should be selected.

The solution table for to_date('01-jan-19') would look like this:

This would be then output line in the procedure.

Should I select to correct tuple and output line it or would it be best to just bulk collect everything and then check in a for loop with an if statement what tuple I need to display.

What I have so far:

A select statement with the tuples I am looking for:

create or replace procedure print_inf_value(closingDate Date) is
cursor d1 (closingDate Date) is
select t.attr, t.dateOfValue, t.price
from ( 
  select i.*,
    row_number() over (
      partition by attr 
      order by case when dateOfValue = closingdate then 1 else 2 end, dateOfValue desc
    ) rn
  from InformationValues i
) t
where t.rn = 1;

BEGIN

dbms_output.put_line('Information             Value   ');
dbms_output.put_line('--------------------------------');
FOR d1_rec IN d1 LOOP
        dbms_output.put_line(d1_rec.attr || '             ' || d1_rec.price );
END LOOP;

END;

Or a procedure where I bulk collect everything and then I need to sort out what tuple I need:

create or replace procedure print_inf_value(closingDate Date) is
TYPE d1 IS TABLE OF informationvalues%rowtype;
emps d1; 

begin select * bulk collect into emps 
from informationvalues;

FOR i IN 1 .. emps.COUNT LOOP
if emps(i).dateofvalue = closingDate then
dbms_output.put_line(emps(i).attr || '             ' || emps(i).price );
/*else*/

end if;
END LOOP;
END;

Both are not working right, so what am I missing to display tuple with the correct date.

Answer 1

Please try:

CREATE OR REPLACE PROCEDURE print_inf_value (closingDate DATE)
IS
BEGIN
   DBMS_OUTPUT.put_line (RPAD ('ATTR', 20) || RPAD ('PRICE', 20));

   FOR o
      IN (select attr, trim(case when price < 1 then to_char(price,90.9) else to_char(price) end) price from (
            select attr, price, dateofvalue,
            row_number() over (partition by attr order by dateofvalue desc) rn from informationvalues
            ) i where dateofvalue = closingdate
            or (rn = 1 and not exists (select 1 from informationvalues iv where iv.attr = i.attr and dateofvalue = closingdate) ) 
        )
   LOOP
      DBMS_OUTPUT.put_line (RPAD (o.attr, 20) || RPAD ( o.price, 20));
   END LOOP;
END;

Sample execution:

set serveroutput on;

begin
    print_inf_value(date'2019-01-01');
end;

Output:

ATTR                PRICE               
age                 2                   
electronics         0.5               
gender              3                   
hobbies             0.5               
homeAddress         7                   
maritalStatus       1                   
mobilePhone         5                   
musicTaste          0.1               
socialContacts      1