以下是@Scott Langham用简单的NULL处理给出的答案:

SELECT
      o.OrderId,
      CASE WHEN (o.NegotiatedPrice > o.SuggestedPrice OR o.SuggestedPrice IS NULL) 
         THEN o.NegotiatedPrice 
         ELSE o.SuggestedPrice
      END As MaxPrice
FROM Order o

为什么不尝试IIF功能(需要SQL Server 2012及更高版本)

IIF(a>b, a, b)

就是这样。

(额外提示:小心a或b是否为空，因为在这种情况下，>b的结果将为假。因此，如果任意一个为空，则返回结果为b)(同样根据系统设计，列为空也不是一个好的实践)

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

在MemSQL中执行以下操作:

-- DROP FUNCTION IF EXISTS InlineMax;
DELIMITER //
CREATE FUNCTION InlineMax(val1 INT, val2 INT) RETURNS INT AS
DECLARE
  val3 INT = 0;
BEGIN
 IF val1 > val2 THEN
   RETURN val1;
 ELSE
   RETURN val2;
 END IF; 
END //
DELIMITER ;

SELECT InlineMax(1,2) as test;

我不这么想。我那天想要这个。我最接近的说法是:

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

DECLARE @MAX INT
@MAX = (SELECT MAX(VALUE) 
               FROM (SELECT 1 AS VALUE UNION 
                     SELECT 2 AS VALUE) AS T1)