Create a View, function or stored procedure for query?

Question

Hi All,
I like to know how I can create a view or function for the query below. If its going to be a function or stored procedure will I be able to union it with another view?
DECLARE
@BegDate DATE,
@EndDate DATE
SELECT
@BegDate = MIN(vl.VoidStartDate),
@EndDate = MAX(vl.LetDate)
FROM #VoidLoss vl
;WITH d(d) AS (
SELECT TOP (DATEDIFF(dd, @BegDate, @EndDate))
DATEADD(dd, ROW_NUMBER() OVER (ORDER BY (SELECT NULL)) -1, @BegDate)
FROM sys.all_objects o
), cal AS (
SELECT
d.d,
MONTH(d.d) AS m,
YEAR(d.d) AS y
FROM d
SELECT
vl.History_IND,
vl.PropCode,
vl.VoidCategory,
vl.ControlGroup,
CASE WHEN vl.VoidStartDate < MIN(cal.d) THEN MIN(cal.d) ELSE vl.VoidStartDate END AS VoidStartDate,
CASE WHEN vl.LetDate > MAX(cal.d) THEN MAX(cal.d) ELSE vl.LetDate END AS LetDate,
vl.MarketRent,
DATENAME(mm, CAST('1900-' + CAST(cal.m AS VARCHAR(2)) + '-1' AS DATE)) AS [Month],
cal.y AS [Year],
COUNT(*) AS DaysVoid,
COUNT(*) * vl.MarketRent AS VoidLoss
FROM
#VoidLoss vl
JOIN cal
ON cal.d BETWEEN DATEADD(dd, 1, vl.VoidStartDate) AND vl.LetDate
GROUP BY
vl.History_IND,
vl.PropCode,
vl.VoidCategory,
vl.ControlGroup,
vl.VoidStartDate,
vl.LetDate,
vl.MarketRent,
cal.m,
cal.y
ORDER BY
vl.History_IND,
vl.PropCode,
vl.VoidStartDate
Thanks

Answer 1

A view or an inline-function is a single query, so this part does not fit in:
DECLARE
@BegDate DATE,
@EndDate DATE
SELECT
@BegDate = MIN(vl.VoidStartDate),
@EndDate = MAX(vl.LetDate)
FROM #VoidLoss vl
And you cannot have it multi-statement function either, since you cannot refer to temp tables in such a function. In any case, using a multi-statement function in a view definition or nest it in another function definition is likely to be a performance disaster.
The sole alternative that remains as long as you have the temp table is a stored procedure. You cannot use a stored procedure in a view or a function.
Erland Sommarskog, SQL Server MVP, [email protected]