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; 

Table:

CREATE TABLE SCOTT.EMPLOYEE (    EMP_ID       INTEGER                          NOT NULL,    EMP_FNAME    VARCHAR2(30 BYTE)                NOT NULL,    EMP_LNAME    VARCHAR2(30 BYTE)                NOT NULL,    EMP_ADDRESS  VARCHAR2(50 BYTE)                NOT NULL,    EMP_PHONE    CHAR(10 BYTE)                    NOT NULL,    EMP_GENDER   CHAR(1 BYTE) ) 

Error:

00907-missing right parantheses

Please provide your inputs.

Answer 1

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 

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;