将内联SQL移动为内部联接查询.所以你会有类似...

Move the inline SQL to be a inner join query. So you'd have something like...

SELECT  DATE_FORMAT(OrderDate,'%M %Y') AS OrderMonth, COUNT(OrderID) AS TotalOrders, SUM(OrderTotal) AS TotalAmount,  Z.OrderCustomerFK, Z.CustomerName, z.OrderTotal as CustomerTotal   
  FROM Orders     
  INNER JOIN (SELECT DATE_FORMAT(OrderDate,'%M %Y') as Mon, OrderCustomerFK, CustomerName, SUM(OrderTotal) as OrderTotal 
                FROM Orders 
               GROUP BY  DATE_FORMAT(OrderDate,'%M %Y'), OrderCustomerFK, CustomerName ORDER BY SUM(OrderTotal) DESC LIMIT 1) Z
          ON Z.Mon = DATE_FORMAT(OrderDate,'%M %Y')
    GROUP BY DATE_FORMAT(OrderDate,'%m%y'), Z.OrderCustomerFK, Z.CustomerName
    ORDER BY DATE_FORMAT(OrderDate,'%y%m') DESC