SQL SELECT If (a="") Then change b value

Question

This seems like a simple question, but I haven't been able to find an answer. I am basically trying to do this:

SELECT * FROM table1
IF(columnA > 0) BEGIN
columnB = 'Greater than 0'
END

I don't want the value to change in the table, I just want it to change in the result. ANy suggestions?

Answer 1

SELECT  ColumnA
        , case when ColumnA > 0 then 'Greater than 0' else ColumnB END AS ColumnB 
FROM    table1;

Answer 2

This should work:

SELECT columnA, IIF(columnA > 0, 'Greater than 0', columnB)
  FROM table1;