I wrote the following query, but in the WHERE clause I used specific dates for a date range. I want the date range to be calculated automatically, that is, a period of 90 days until today. How can i do this?
SELECT Orders.Day, Orders.Month, Orders.Year, Orders.Orders_Count,Orders.PaymentAmount, Orders.Total_Payment_Authorized, Orders.ShipCity, Orders.Total_Payment_Received, Orders.SalesTax1, Orders.SalesTax2, Orders.SalesTax3, Orders.TotalShippingCost, Orders.OrderDetails_Count, Orders.Quantity, Orders.COGS, Orders.Profit, Orders.ProfitMargin FROM (SELECT Orders.Day,Orders.Month,Orders.Year,Orders.Orders_Count, Orders.PaymentAmount,Orders.Total_Payment_Authorized,Orders.ShipCity,Orders.Total_Payment_Received,Orders.SalesTax1,Orders.SalesTax2,Orders.SalesTax3, Orders.TotalShippingCost,OrderDetails.OrderDetails_Count, OrderDetails.Quantity,OrderDetails.COGS,OrderDetails.Profit,OrderDetails.ProfitMargin FROM (SELECT DATEPART(DD, Orders.OrderDate) AS Day, DATEPART(MM, Orders.OrderDate) AS Month,DATEPART(YY, Orders.OrderDate) AS Year, Max(Orders.OrderDate) As OrderDate ,Max(Orders.ShipDate) As ShipDate, Count(Orders.OrderID) As Orders_Count, Sum(Orders.PaymentAmount) AS PaymentAmount, Sum(Orders.Total_Payment_Authorized) AS Total_Payment_Authorized,Orders.ShipCity AS ShipCity, Sum(Orders.Total_Payment_Received) AS Total_Payment_Received, Sum(Orders.SalesTax1) AS SalesTax1,Sum(Orders.SalesTax2) AS SalesTax2 , Sum(Orders.SalesTax3) AS SalesTax3, Sum(Orders.TotalShippingCost) AS TotalShippingCost FROM (((Orders WITH(NOLOCK) LEFT JOIN PaymentMethods WITH(NOLOCK) ON Orders.PaymentMethodID = PaymentMethods.PaymentMethodID) LEFT JOIN ShippingMethods WITH(NOLOCK) ON Orders.ShippingMethodID = ShippingMethods.ShippingMethodID) LEFT JOIN Customers WITH(NOLOCK) ON Orders.CustomerID = Customers.CustomerID) WHERE Orders.OrderStatus <> 'Cancelled' GROUP BY Orders.ShipCity, DATEPART(DD, Orders.OrderDate),DATEPART(MM, Orders.OrderDate),DATEPART(YY, Orders.OrderDate)) Orders INNER JOIN (SELECT DATEPART(DD, Orders.OrderDate) AS Day,DATEPART(MM, Orders.OrderDate) AS Month,DATEPART(YY, Orders.OrderDate) AS Year, Count(OrderDetails.OrderDetailID) As OrderDetails_Count, Sum(OrderDetails.Quantity) AS Quantity, Sum(OrderDetails.Vendor_Price * OrderDetails.Quantity) AS COGS, Case When SUM(Vendor_Price) IS NULL Then null Else Sum((Case When OrderDetails.ProductCode like 'DSC-%' Then OrderDetails.ProductPrice - ISNULL(OrderDetails.Vendor_Price,0) Else OrderDetails.ProductPrice - OrderDetails.Vendor_Price End) * OrderDetails.Quantity) End AS Profit, CASE SUM(OrderDetails.ProductPrice * OrderDetails.Quantity) WHEN 0 THEN 0 ELSE ROUND(((SUM(OrderDetails.ProductPrice * OrderDetails.Quantity) - SUM(OrderDetails.Vendor_Price * OrderDetails.Quantity)) / SUM(OrderDetails.ProductPrice * OrderDetails.Quantity)) * 100, 1) END AS ProfitMargin FROM (((Orders WITH(NOLOCK) LEFT JOIN PaymentMethods WITH(NOLOCK) ON Orders.PaymentMethodID = PaymentMethods.PaymentMethodID) LEFT JOIN ShippingMethods WITH(NOLOCK) ON Orders.ShippingMethodID = ShippingMethods.ShippingMethodID) LEFT JOIN Customers WITH(NOLOCK) ON Orders.CustomerID = Customers.CustomerID) LEFT JOIN OrderDetails WITH(NOLOCK) ON Orders.OrderID = OrderDetails.OrderID WHERE Orders.OrderStatus <> 'Cancelled' AND DATEDIFF(dd, Orders.OrderDate, '03/01/2012') <= 0 AND DATEDIFF(dd, Orders.OrderDate, '06/30/2012') >= 0 AND Orders.ShipPostalCode IN ('96704','96710','96718','96719','96720','96721','96725','96726','96727','96728','96737','96738','96739','96740','96743','96745','96749','96750','96755','96760','96764','96771','96772','96773','96774','96776','96777','96778','96780','96781','96783','96785') GROUP BY Orders.ShipCity, DATEPART(DD, Orders.OrderDate),DATEPART(MM, Orders.OrderDate), DATEPART(YY, Orders.OrderDate)) OrderDetails ON Orders.Day = OrderDetails.Day AND Orders.Month = OrderDetails.Month AND Orders.Year = OrderDetails.Year) Orders ORDER BY Orders.Day DESC, Orders.Month DESC,Orders.Year DESC