CHOOSE function is the logical function. It is similar to SWITCH function in .NET. Choose function will return the item at the specified index from the list of values .

-- below query will return "SQLDBPool-2"as output
Select CHOOSE(2,'SQLDBPool','SQLDBPool-2','SQLDBPool-3')

-- below query will return "Thursday"as output
DECLARE @day as int
set @day = 5
SELECT Choose(@day,'Sunday','Monday', 'Tuesday', 'Wednesday','Thursday','Friday','Saturday')