Question

let say i do select score from table1. this will return result

score
----
0
20
40

how to use case, to change the output to if 0->strongly not agree 20->agree 40->very agreed

Answer 1

I think thats what you want:

select 
  case 
    when score >= 40 then 'very agreed'
    when score >= 20 then 'agree'
    else 'strongly not agree'
  end
from table1