When you have a long series of mutually exclusive conditions and the comparison is numeric, using a SELECT group is slightly more efficient than using IF-THEN or IF-THEN-ELSE statements because CPU time is reduced.
The syntax for SELECT WHEN is as follows :
SELECT (condition);
WHEN (1) x=x;
WHEN (2) x=x*2;
OTHERWISE x=x-1;
END;
Example :
SELECT (str);
WHEN ('Sun') wage=wage*1.5;
WHEN ('Sat') wage=wage*1.3;
OTHERWISE DO;
wage=wage+1;
bonus=0;
END;
END;
