SELECT CASE - a control flow statement that executes one of several
              statement blocks depending on the value of an expression
Syntax
  SELECT CASE testexpression
  [CASE expressionlist1]
    [statementblock-1]
  [CASE expressionlist2
    [statementblock-2]] ...
 
  [CASE ELSE
    [statementblock-n]]
  END SELECT
 
    - testexpression is any numeric or string expression.
    - expressionlist contains one or more expressions of the same type as
      testexpression. The IS keyword must precede any relational operators
      in an expression.
    - statementblock consists of any number of statements on one or more
      lines.