Question

我已经在SQL Server查询上挣扎了一段时间，并意识到我必须得到比我更了解SQL Server（更多）的人的帮助。

环境：SQL Server 2008

SELECT      
    t1.SUPPL_ORDERNO, 
    t2.OUR_ORDER,
    t3.CUST_INVOICE
FROM t1 

    LEFT OUTER JOIN t2 
        ON t1.SUPPL_ORDERNO = t2.ORDER_REM5 

    LEFT OUTER JOIN t3
        ON t2.ORDER_REM5  = t3.INV_REM5

GROUP BY t1.SUPPL_ORDERNO, t2.OUR_ORDER, t3.CUST_INVOICE
ORDER BY t1.SUPPL_ORDERNO,t3.CUST_INVOICE

这是我通过上述查询获得的结果：

SUPPL_ORDERNO                  OUR_ORDER CUST_INVOICE
------------------------------ --------- ------------
143914                         64228     179890
143914                         64228     179935
143914                         64228     179995
143914                         64228     179999
143914                         64228     180067
143914                         64228     180148
326042                                   
326052                         64549     180219
326086                         64633

我为每个CUST_INVOICE和SUPPL_ORDERNO组合获得了多个OUR_ORDER，但我只想返回最新的CUST_INVOICE（=最大发票号）。

这是我想要返回的结果：

SUPPL_ORDERNO                  OUR_ORDER CUST_INVOICE
------------------------------ --------- ------------
143914                         64228     180148
326042                                   
326052                         64549     180219
326086                         64633

要点：

如果CUST_INVOICE和SUPPL_ORDERNO的组合有多个（1）OUR_ORDER，我只想显示数字最大的CUST_INVOICE
如果没有OUR_ORDER且没有CUST_INVOICE我希望它显示为空
如果有OUR_ORDER且没有CUST_INVOICE我希望它显示为空

任何帮助将不胜感激！

Answer 1

从GROUP BY中删除t3.CUST_INVOICE并使用MAX（t3.CUST_INVOICE）函数进入SELECT语句

SELECT t1.SUPPL_ORDERNO, t2.OUR_ORDER, MAX(t3.CUST_INVOICE) AS CUST_INVOICE
FROM t1 LEFT JOIN t2 ON t1.SUPPL_ORDERNO = t2.ORDER_REM5 
        LEFT JOIN t3 ON t2.ORDER_REM5  = t3.INV_REM5
GROUP BY t1.SUPPL_ORDERNO, t2.OUR_ORDER
ORDER BY t1.SUPPL_ORDERNO, t3.CUST_INVOICE

SQLFiddle

上的简单示例

Answer 2

解决此问题的最佳方法是使用row_number()。这会为事物添加一个序列号，在这种情况下是每个订单中的发票编号：

select suppl_orderno, our_order, cust_invoice
from (SELECT t1.SUPPL_ORDERNO, t2.OUR_ORDER, t3.CUST_INVOICE,
             row_number() over (partition by t1.SUPPL_ORDERNO, t2.OUR_ORDER order by t3.cust_invoice desc) as seqnum
      FROM t1 LEFT OUTER JOIN
           t2 
           ON t1.SUPPL_ORDERNO = t2.ORDER_REM5 LEFT OUTER JOIN
           t3
           ON t2.ORDER_REM5  = t3.INV_REM5
     ) t
where seqnum - 1
ORDER BY SUPPL_ORDERNO,CUST_INVOICE

通过按降序排序发票，最新版本的值为“1”，用于过滤器。

从SQL Server加入获取最大值

2 个答案: