How to replace null values with a text?

Question

I need to display Employee last_name and their commission amount from employees table in Oracle SQL, but the condition is if it encounter NULL valu

Answer 1

You can use case expression:

select last_name
     , case when commision_pct is null then 'No Commission' else commision_pct end    
from employees;

or coalesce:

select last_name
     , coalesce(commision_pct, 'No Commission')
from employees;

or nvl:

 select last_name
     , nvl(commision_pct, 'No Commission')
from employees;

P.S. In case commision_pct's datatype is not varchar you should also use cast or to_char.