ORACLE IIF Statement

Question

I get an error while writing the IIF statement, table and the statement given below.

Statement:

SELECT IIF(EMP_ID=1,\'True\',\'False\') from Employee;
         


        

Answer 1

In PL/SQL, there is a trick to use the undocumented OWA_UTIL.ITE function.

SET SERVEROUTPUT ON

DECLARE
    x   VARCHAR2(10);
BEGIN
    x := owa_util.ite('a' = 'b','T','F');
    dbms_output.put_line(x);
END;
/

F

PL/SQL procedure successfully completed.

Answer 2

Two other alternatives:

3. a combination of NULLIF and NVL2. You can only use this if emp_id is NOT NULL, which it is in your case:

   select nvl2(nullif(emp_id,1),'False','True') from employee;
   

4. simple CASE expression (Mt. Schneiders used a so-called searched CASE expression)

   select case emp_id when 1 then 'True' else 'False' end from employee;
   

Answer 3

Oracle doesn't provide such IIF Function. Instead, try using one of the following alternatives:

DECODE Function:

SELECT DECODE(EMP_ID, 1, 'True', 'False') from Employee

CASE Function:

SELECT CASE WHEN EMP_ID = 1 THEN 'True' ELSE 'False' END from Employee