关于MySQL JOIN OR WHERE语句的问题

Question

这是我使用的SQL语句：

    SELECT  a.Customer_ID, a.Customer_Name,c.Service_ID
          , c.Service_Name,f.Service_Type,c.Service_Price
          , e.Bill_ID, e.Bill_Day, e.Due_Bill_Day 
   FROM customers a,customer_service b,services c
        , billing_services d, billing e, services_type f 
   WHERE a.Customer_ID = b.Customer_ID AND b.Service_ID = c.Service_ID 
        AND c.Service_ID = d.Service_ID AND d.Bill_ID = e.Bill_ID 
        AND c.Service_Type = f.ID

我对SQL语句的问题很少。 我可以知道上层语句与使用连接相同吗？ （性能与特点？） 2.我想将结果显示一次，如果重复，差异结果显示两次，用于账单对账单。

谢谢。

Answer 1

SELECT  max(a.Customer_ID), max(a.Customer_Name),max(c.Service_ID)
              , max(c.Service_Name),max(f.Service_Type),max(c.Service_Price)
              , max(e.Bill_ID), max(e.Bill_Day), max(e.Due_Bill_Day) 
       FROM customers a inner join customer_service b on(a.Customer_ID = b.Customer_ID) inner join services c on (b.Service_ID = c.Service_ID)
            inner join billing_services d on(c.Service_ID = d.Service_ID) inner join billing e on(d.Bill_ID = e.Bill_ID ) inner join services_type f on( c.Service_Type = f.ID)
            group by  a.Customer_ID, a.Customer_Name,c.Service_ID
              , c.Service_Name,f.Service_Type,c.Service_Price
              , e.Bill_ID, e.Bill_Day, e.Due_Bill_Day 

试试此代码