Use a formula to alias, like so:
SELECT {myfield}
CASE 1:
"Data Entry"
CASE 2:
"Missing Data"
CASE 3:
"Old Data"
CASE 4:
"Virtual Data"
DEFAULT:
"Good Data";
Or, since you are using simple numbers, you can use an array-based solution.
["Data Entry","Missing Data","Old Data","Virtual...