SQL - _etblTerms - Unpivot _as_ARAP_Terms_Unpivot

CREATE OR ALTER VIEW _as_ARAP_Terms_Unpivot
 AS
/*TO VERIFY: is 0 based or 1 based.
2nd note: might need to handle Interval 7 if null.*/
/*Usage:
SELECT * FROM Client C
	LEFT JOIN _as_ARAP_Terms_Unpivot T ON T.iTermID = C.iAgeingTermID AND C.AccountTerms = T.IntervalNumber 
*/
SELECT iTermID, iModule, IntervalDay, IntervalValue,CASE IntervalDay
        WHEN 'iInterval1Days' THEN 1-1
        WHEN 'iInterval2Days' THEN 2-1
        WHEN 'iInterval3Days' THEN 3-1
        WHEN 'iInterval4Days' THEN 4-1
        WHEN 'iInterval5Days' THEN 5-1
        WHEN 'iInterval6Days' THEN 6-1
        WHEN 'iInterval7Days' THEN 7-1
    END AS IntervalNumber
    FROM
    (
        SELECT iTermID, iModule, iInterval1Days, iInterval2Days, iInterval3Days, iInterval4Days, iInterval5Days, iInterval6Days, COALESCE(iInterval7Days,iInterval6Days+1) iInterval7Days
        FROM dbo._etblTerms
    ) AS t
    UNPIVOT
    (
        IntervalValue FOR IntervalDay IN (iInterval1Days, iInterval2Days, iInterval3Days, iInterval4Days, iInterval5Days, iInterval6Days, iInterval7Days)
    ) AS unpivoted