Question

I want to change the return value of the Select statement. I need to do it in SQL.
Say, we have

SELECT CourseCode FROM Course WHERE CourseName='?' -- '?' refers to user value

If the user value is null or if the course name is not in the database, I would like the select statement to return ‘Not applicable’.

Answer 1

SELECT CourseCode FROM Course WHERE CourseName='?'

UNION ALL

SELECT 'Not Applicable'
WHERE NOT EXISTS (
    SELECT CourseCode FROM Course WHERE CourseName='?'
)