SQL根据一列中的最大值选择多列 [英] SQL Selecting multiple columns based on max value in one column

问题描述

好，因此我对其他解决方案没有任何帮助.所以这就是我想要做的. 我需要选择多列的行，其中一列的值为最大值.

OK so I have looked theough the other solutions an no help. So here is what I am trying to do. I need to select the row with multiple columns where the value in one column is the max value.

这是示例数据

    orderfileid item number item cost   warehouse
    1           1234        3.45             ATL
    1           2345        1.67             DFW
    3           2345        2.45             NYY
    3           678         2.4              ORD
    2           1234        1.67             DFW

我需要选择整行，其中orderfileid是每个唯一商品编号的最大值

I need to select the entire row where the orderfileid is the max for each unique item number

返回的数据集应该看起来像

the returned dataset should look like

    orderfileid item number item cost   warehouse
    2           1234        1.67             DFW
    3           2345        2.45             NYY
    3           6789        2.4              ORD

我想我尝试了我能想到的select max(orderfileid)的每种组合

I think i tried every combination of select max(orderfileid) i can think of

将寻求任何帮助. 谢谢

Any help would be appriciated. thanks

推荐答案

您需要在子查询中找到MAX值，然后使用这些结果将其连接到主表中以检索列.

You need to find your MAX values in a subquery, then use those results to join to your main table to retrieve the columns.

SELECT t.OrderFileId, t.ItemNumber, t.ItemCost, t.Warehouse
    FROM YourTable t
        INNER JOIN (SELECT ItemNumber, MAX(OrderFileId) AS MaxOrderId
                        FROM YourTable
                        GROUP BY ItemNumber) q
            ON t.ItemNumber = q.ItemNumber
                AND t.OrderFileId = q.MaxOrderId

这篇关于SQL根据一列中的最大值选择多列的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！