A few examples to show, just incase:
Inline Table Valued
CREATE FUNCTION MyNS.GetUnshippedOrders()
RETURNS TABLE
AS
RETURN SELECT a.SaleId, a.CustomerID, b.Qty
FROM Sales.Sales a INNER JOIN Sales.SaleDetail b
ON a.SaleId = b.SaleId
INNER JOIN Production.Product c ON b.ProductID = c.ProductID
WHERE a.ShipDate IS NULL
GO
Multi Statement Table Valued
CREATE FUNCTION MyNS.GetLastShipped(@CustomerID INT)
RETURNS @CustomerOrder TABLE
(SaleOrderID INT NOT NULL,
CustomerID INT NOT NULL,
OrderDate DATETIME NOT NULL,
OrderQty INT NOT NULL)
AS
BEGIN
DECLARE @MaxDate DATETIME
SELECT @MaxDate = MAX(OrderDate)
FROM Sales.SalesOrderHeader
WHERE CustomerID = @CustomerID
INSERT @CustomerOrder
SELECT a.SalesOrderID, a.CustomerID, a.OrderDate, b.OrderQty
FROM Sales.SalesOrderHeader a INNER JOIN Sales.SalesOrderHeader b
ON a.SalesOrderID = b.SalesOrderID
INNER JOIN Production.Product c ON b.ProductID = c.ProductID
WHERE a.OrderDate = @MaxDate
AND a.CustomerID = @CustomerID
RETURN
END
GO
Is there an advantage to using one type (in-line or multi statement) over the other? Is there certain scenarios when one is better than the other or are the differences purely syntactical? I realise the two example queries are doing different things but is there a reason I would write them in that way?
Reading about them and the advantages/differences haven’t really been explained.
