Выбор строк с MAX (значение столбца), DISTINCT другим столбцом в SQL

Question

У меня есть две таблицы, с которыми мне сложно. OrderHed & UD11. OrderHed имеет 1 значение для OrderNum = 70960, но UD11 имеет 4 записи для 70960.

Я пытаюсь вернуть максимальное значение UD11.Key5 как отдельную запись - что я делаю неправильно?

Спасибо!

SELECT TOP (100) PERCENT OrderHed.OrderNum, 
    OrderHed.OpenOrder, 
    OrderHed.OrderDate, 
    OrderRel.Plant, 
    OrderHed.EntryPerson, 
    OrderHed.Company, 
    Erp.Customer.CustID, 
    Erp.Customer.NAME, 
    Erp.InvcDtl.InvoiceNum, 
    SUM(OrderDtl.ExtPriceDtl) AS Expr1, 
    OrderHed.PONum, 
    Ice.UD11.Key1, 
    Ice.UD11.Key2, 
    Ice.UD11.Key3, 
    Ice.UD11.Key4, 
    MAX(Ice.UD11.Key5) AS Expr2, 
    Ice.UD11.Character01, 
    Ice.UD11.Number01, 
    Ice.UD11.Date01, 
    Ice.UD11.Date02, 
    Ice.UD11.Date03, 
    Ice.UD11.ShortChar01, 
    Ice.UD11.ShortChar02, 
    Ice.UD11.ShortChar03, 
    Ice.UD11.ShortChar04, 
    Ice.UD11.ShortChar05, 
    OrderHed.OrderComment 
FROM Erp.Customer 
RIGHT JOIN Ice.UD11 
RIGHT JOIN Erp.OrderHed AS OrderHed ON Ice.UD11.Company = OrderHed.Company 
    AND Ice.UD11.Key1 = OrderHed.OrderNum 
LEFT JOIN Erp.OrderRel AS OrderRel 
RIGHT JOIN Erp.OrderDtl AS OrderDtl ON OrderRel.Company = OrderDtl.Company 
    AND OrderRel.OrderNum = OrderDtl.OrderNum 
    AND OrderRel.OrderLine = OrderDtl.OrderLine ON OrderHed.Company = OrderDtl.Company 
    AND OrderHed.OrderNum = OrderDtl.OrderNum ON Erp.Customer.Company = OrderHed.Company 
    AND Erp.Customer.CustNum = OrderHed.CustNum LEFT JOIN Erp.InvcDtl RIGHT JOIN Erp.ShipDtl ON Erp.InvcDtl.Company = Erp.ShipDtl.Company 
    AND Erp.InvcDtl.OrderNum = Erp.ShipDtl.OrderNum 
    AND Erp.InvcDtl.OrderLine = Erp.ShipDtl.OrderLine 
    AND Erp.InvcDtl.OrderRelNum = Erp.ShipDtl.OrderRelNum ON OrderRel.Company = Erp.ShipDtl.Company 
    AND OrderRel.OrderNum = Erp.ShipDtl.OrderNum 
    AND OrderRel.OrderLine = Erp.ShipDtl.OrderLine 
    AND OrderRel.OrderRelNum = Erp.ShipDtl.OrderRelNum GROUP BY OrderHed.OrderNum, 
    OrderHed.OrderDate, 
    OrderRel.Plant, 
    OrderHed.EntryPerson, 
    OrderHed.Company, 
    OrderHed.OpenOrder, 
    Erp.Customer.CustID, 
    Erp.Customer.NAME, 
    Erp.InvcDtl.InvoiceNum, 
    OrderHed.PONum, 
    Ice.UD11.Key1, 
    Ice.UD11.Key2, 
    Ice.UD11.Key3, 
    Ice.UD11.Key4, 
    Ice.UD11.Character01, 
    Ice.UD11.Number01, 
    Ice.UD11.Date01, 
    Ice.UD11.Date02, 
    Ice.UD11.Date03, 
    Ice.UD11.ShortChar01, 
    Ice.UD11.ShortChar02, 
    Ice.UD11.ShortChar03, 
    Ice.UD11.ShortChar04, 
    Ice.UD11.ShortChar05, 
    OrderHed.OrderComment HAVING (OrderHed.Company = N'011') 
    AND (Erp.InvcDtl.InvoiceNum IS NULL) 
    AND (OrderHed.OrderNum = 70960) 

Answer 1

SELECT * 
FROM (
     SELECT *, 
       ROW_NUMBER() OVER (PARTITION BY OrderNum ORDER BY key5 DESC) rn 
     FROM (... /* my huge query */) q 
     ) q 
WHERE rn = 1