Objective :

Oracle : NVl2,

PostgreSQL COALESCE : Return the first non-NULL argument

select empno, ename, sal,job, comm , nvl2(comm,12*sal+comm,12*sal) as yearsal from emp where JOB='SALESMAN'

Postgresql AND MYSQL:

  select empno, ename, sal,job, COMM,COALESCE((12*sal+comm),12*sal)as yearsal from emp where JOB='SALESMAN'

EMP Table

Microsoft Office Excel

Oracle:

 
PostgreSQL
MySQL