How to add compare select statement in if() condition oracle pl-sql

Question

How to add compare select statement in if() condition in Oracle pl-sql

IF( (v_c1.int_rate = '0') 
    AND (local_type_advances in (SELECT DISTINCT(REF_CODE) 
                                 FROM XYZ 
                                 WHERE REF_REC_TYPE = '39' AND DEL_FLG = 'N'         
                                   AND REF_CODE BETWEEN '1' AND '50' )))

where select query generate following output

'31','32','33'

now as below if I hardcode it then it works fine but in query doesn't works

IF( (v_c1.int_rate='0') AND (local_type_advances in ('31','32','33')))

Answer 1

What I have done is, I have stored result of that select statment in localvariable as varchar2. And added this local varchar in that if condition's in clause as result instead of that select statment

select '''' || listagg(REF_CODE, ''',''' ) within group (order by REF_CODE) || '''' as type_advances into local_type_advances_list from RCT@ADF2FIN where REF_REC_TYPE = '39' AND DEL_FLG = 'N' AND REF_CODE BETWEEN '1' AND '50';


IF( (v_c1.int_rate='0') AND (local_type_advances in (local_type_advances_list)) )

Answer 2

Since you can't have a select statement in an IN clause, break it into two pieces. Select the range you need to search into a variable, then search that variable to see if the value is in there. Here is a working example using LISTAGG() to return a comma-separated list into a variable and REGEXP_LIKE to test the list in the variable to see if the value is in the list. X_TBL has one column, X_COL that contains three rows, '31', '32' and '33' respectively.

declare
  local_type_advance_string varchar2(50);        -- Holds the list returned from 
                                                 --   the query.
  local_type_advance_nbr    varchar2(2) := '32'; -- Value to test the list for.
begin

  --  Use listagg() to select a comma-separated list into a string variable.
  --  X_TBL is the table, X_COL is the column.
  SELECT LISTAGG(X_COL, ',') WITHIN GROUP( ORDER BY X_COL)
  into local_type_advance_string
  FROM X_TBL;

  --dbms_output.put_line(local_type_advance_string);

  IF regexp_like(local_type_advance_string, '(^|\W)'|| 
                 local_type_advance_nbr || '(\W|$)') then
    dbms_output.put_line(local_type_advance_nbr || ' Is in there!');
  else
    dbms_output.put_line(local_type_advance_nbr || ' Is not found');
  end if;

end;

The regular expression allows for the position of the search number no matter if it's at the beginning, middle or end of the list.

Run via Toad:

32 Is in there!

Answer 3

Even if you could put that big, honkin' select in there, I would recommend keeping the if statement simple for maintainability. This works and is a lot clearer, especially if you add sensible comments:

create table XYZ(
  REF_REC_TYPE  int,
  DEL_FLG       char( 1 ),
  REF_CODE      int
);

insert into XYZ
select 39, 'Y', 28 from dual union all
select 39, 'Y', 29 from dual union all
select 39, 'Y', 30 from dual union all
select 39, 'N', 31 from dual union all
select 39, 'N', 32 from dual union all
select 39, 'N', 33 from dual union all
select 39, 'Y', 34 from dual union all
select 39, 'Y', 35 from dual union all
select 39, 'Y', 36 from dual;

DECLARE
  int_rate            INT := 0;
  local_type_advances INT := 32;
  found               INT;
BEGIN
  -- See if we have any whatever
  SELECT  count(*)
  INTO    found
  FROM    XYZ 
  WHERE   REF_REC_TYPE = 39
    AND   DEL_FLG = 'N'         
    AND   REF_CODE = local_type_advances;

  IF int_rate = 0
     AND found > 0 THEN
        dbms_output.put_line( 'True: ' || found );
    ELSE
        dbms_output.put_line( 'False: ' || found );
    END IF;
END;

Btw, this doesn't execute in SqlFiddle for some reason. As it happens, I found a perfectly good Oracle DB sitting in a drawer under some old napkins. So I can verify this is good code.