Select SP.SalesPersonID, Sum(SubTotal)FromSales.SalesPerson SPINNER JOIN Sales.SalesOrderHeader SOH ON SP.SalesPersonID = SOH.SalesPersonID where SOH.OrderDate Between '1/1/2003' and '1/31/2003' OR SOH.OrderDate is nullGroup By SP.SalesPersonID

Select SP.SalesPersonID, Sum(SubTotal)FromSales.SalesPerson SPLEFT JOIN Sales.SalesOrderHeader SOH ON SP.SalesPersonID = SOH.SalesPersonID where SOH.OrderDate Between '1/1/2003' and '1/31/2003' Group By SP.SalesPersonID

Select SP.SalesPersonID, Sum(SubTotal)FromSales.SalesPerson SPLEFT JOIN Sales.SalesOrderHeader SOH ON SP.SalesPersonID = SOH.SalesPersonID where SOH.OrderDate Between '1/1/2003' and '1/31/2003' OR OrderDate IS NULLGroup By SP.SalesPersonID

Select SP.SalesPersonID, Sum(SubTotal)FromSales.SalesPerson SPLEFT JOIN Sales.SalesOrderHeader SOH ON SP.SalesPersonID = SOH.SalesPersonID and SOH.OrderDate Between '1/1/2003' and '1/31/2003'Group By SP.SalesPersonID