effective date query

SELECT 

    adventureworks_salesorderheader_1.adventureworks_salesorderheader_0_SalesPersonID AS adventureworks_salesorderheader_1_adventureworks_salesorderheader_0_SalesPersonID,

    adventureworks_contact_0.FirstName AS adventureworks_contact_0_FirstName,

    adventureworks_contact_0.LastName AS adventureworks_contact_0_LastName,

    adventureworks_salesorderheader_1.adventureworks_salesorderheader_0_formula0 AS adventureworks_salesorderheader_1_adventureworks_salesorderheader_0_formula0,

    adventureworks_salesorderheader_1.adventureworks_salesorderheader_0_formula1 AS adventureworks_salesorderheader_1_adventureworks_salesorderheader_0_formula1,

    adventureworks_salesorderheader_1.adventureworks_salesorderheader_0_formula2 AS adventureworks_salesorderheader_1_adventureworks_salesorderheader_0_formula2,

    adventureworks_salespersonquotahistory_0.SalesQuota AS adventureworks_salespersonquotahistory_0_SalesQuota,

    adventureworks_salesorderheader_1.adventureworks_salesorderheader_0_formula2 / adventureworks_salespersonquotahistory_0.SalesQuota AS adventureworks_salesorderheader_1_formula0

FROM

    (SELECT 

        adventureworks_salesorderheader_0.SalesPersonID AS adventureworks_salesorderheader_0_SalesPersonID,

            YEAR(adventureworks_salesorderheader_0.OrderDate) AS adventureworks_salesorderheader_0_formula0,

            MONTH(adventureworks_salesorderheader_0.OrderDate) AS adventureworks_salesorderheader_0_formula1,

            SUM(adventureworks_salesorderheader_0.SubTotal) AS adventureworks_salesorderheader_0_formula2

    FROM

        adventureworks.salesorderheader adventureworks_salesorderheader_0

    WHERE

        adventureworks_salesorderheader_0.SalesPersonID = '268'

    GROUP BY adventureworks_salesorderheader_0.SalesPersonID , YEAR(adventureworks_salesorderheader_0.OrderDate) , MONTH(adventureworks_salesorderheader_0.OrderDate)) adventureworks_salesorderheader_1

        JOIN

    adventureworks.salespersonquotahistory adventureworks_salespersonquotahistory_0 ON (adventureworks_salespersonquotahistory_0.SalesPersonID = adventureworks_salesorderheader_1.adventureworks_salesorderheader_0_SalesPersonID

        AND adventureworks_salespersonquotahistory_0.QuotaDate = (SELECT 

            MAX(adventureworks_salespersonquotahistory_1.QuotaDate)

        FROM

            adventureworks.salespersonquotahistory adventureworks_salespersonquotahistory_1

        WHERE

            (adventureworks_salespersonquotahistory_1.SalesPersonID = adventureworks_salespersonquotahistory_0.SalesPersonID

                AND YEAR(adventureworks_salespersonquotahistory_1.QuotaDate) <= adventureworks_salesorderheader_1.adventureworks_salesorderheader_0_formula0

                AND MONTH(adventureworks_salespersonquotahistory_1.QuotaDate) <= adventureworks_salesorderheader_1.adventureworks_salesorderheader_0_formula1)))

        JOIN

    adventureworks.salesperson adventureworks_salesperson_0 ON adventureworks_salesperson_0.SalesPersonID = adventureworks_salesorderheader_1.adventureworks_salesorderheader_0_SalesPersonID

        JOIN

    adventureworks.employee adventureworks_employee_0 ON adventureworks_employee_0.EmployeeID = adventureworks_salesperson_0.SalesPersonID

        JOIN

    adventureworks.contact adventureworks_contact_0 ON adventureworks_contact_0.ContactID = adventureworks_employee_0.ContactID;