Question

 SELECT OrderNumber, FIRST(ShippingName) as ShippingName FROM Orders
 GROUP BY OrderNumber

这会出错，我该怎么做？

Answer 1

SQL Server不支持FIRST功能。

也许你想要

SELECT OrderNumber, MIN(ShippingName) as ShippingName
FROM Orders
GROUP BY OrderNumber

但是，可能不是。相反，我怀疑你的意思是...对于OrderNumber的所有行中的OrderNumber，根据某种顺序选择第一行的ShippingName。

SELECT OrderNumber,
    (
        SELECT TOP 1 ShippingName
        FROM Orders AS OrdersInner
        WHERE OrdersInner.OrderNumber = Orders.OrderNumber
        ORDER BY OrdersInner.OrderDate, OrdersInner.OrderId
    ) as ShippingName
FROM Orders
GROUP BY OrderNumber

但我对你的要求和你的数据库结构做了一些假设。

Answer 2

你可能意思是：

SELECT TOP 1 OrderNumber, ShippingName
FROM Orders
ORDER BY OrderNumber DESC

第一排分组

2 个答案: