以下是一个带有NULL处理的IIF版本(基于Xin的回答):

IIF(a IS NULL OR b IS NULL, ISNULL(a,b), IIF(a > b, a, b))

逻辑如下，如果其中一个值为NULL，则返回非NULL的值(如果两个值都为NULL，则返回NULL)。否则返回较大的值。

MIN也是一样。

IIF(a IS NULL OR b IS NULL, ISNULL(a,b), IIF(a < b, a, b))

其他答案都很好，但如果你不得不担心有NULL值，你可能会想要这个变体:

SELECT o.OrderId, 
   CASE WHEN ISNULL(o.NegotiatedPrice, o.SuggestedPrice) > ISNULL(o.SuggestedPrice, o.NegotiatedPrice)
        THEN ISNULL(o.NegotiatedPrice, o.SuggestedPrice)
        ELSE ISNULL(o.SuggestedPrice, o.NegotiatedPrice)
   END
FROM Order o

你可以这样做:

select case when o.NegotiatedPrice > o.SuggestedPrice 
then o.NegotiatedPrice
else o.SuggestedPrice
end

是的，有。

T-SQL (SQL Server 2022 (16.x))现在支持最大/最小函数:

MAX/MIN作为非聚合函数 现在Azure SQL数据库和SQL托管实例都支持这个功能。它将滚动到下一个版本的SQL Server。

逻辑函数- GREATEST (Transact-SQL) 此函数返回一个或多个表达式列表中的最大值。 最伟大的表达，…n)

在这种情况下:

SELECT o.OrderId, GREATEST(o.NegotiatedPrice, o.SuggestedPrice)
FROM [Order] o;

db < > fiddle演示

如果你使用的是SQL Server 2008(或更高版本)，那么这是更好的解决方案:

SELECT o.OrderId,
       (SELECT MAX(Price)
        FROM (VALUES (o.NegotiatedPrice),(o.SuggestedPrice)) AS AllPrices(Price))
FROM Order o

所有的信用和投票都应该去Sven对一个相关问题的答案，“多列的SQL MAX ?” 我说这是“最佳答案”，因为:

It doesn't require complicating your code with UNION's, PIVOT's, UNPIVOT's, UDF's, and crazy-long CASE statments. It isn't plagued with the problem of handling nulls, it handles them just fine. It's easy to swap out the "MAX" with "MIN", "AVG", or "SUM". You can use any aggregate function to find the aggregate over many different columns. You're not limited to the names I used (i.e. "AllPrices" and "Price"). You can pick your own names to make it easier to read and understand for the next guy. You can find multiple aggregates using SQL Server 2008's derived_tables like so: SELECT MAX(a), MAX(b) FROM (VALUES (1, 2), (3, 4), (5, 6), (7, 8), (9, 10) ) AS MyTable(a, b)

SELECT o.OrderId,   
--MAX(o.NegotiatedPrice, o.SuggestedPrice)  
(SELECT MAX(v) FROM (VALUES (o.NegotiatedPrice), (o.SuggestedPrice)) AS value(v)) as ChoosenPrice  
FROM Order o