以下两个示例中的任何一个都可以工作:

SELECT  MAX(date_columns) AS max_date
FROM    ( (SELECT   date1 AS date_columns
           FROM     data_table         )
          UNION
          ( SELECT  date2 AS date_columns
            FROM    data_table
          )
          UNION
          ( SELECT  date3 AS date_columns
            FROM    data_table
          )
        ) AS date_query

第二个是对拉塞夫克的答案的补充。

SELECT  MAX(MostRecentDate)
FROM    ( SELECT    CASE WHEN date1 >= date2
                              AND date1 >= date3 THEN date1
                         WHEN date2 >= date1
                              AND date2 >= date3 THEN date2
                         WHEN date3 >= date1
                              AND date3 >= date2 THEN date3
                         ELSE date1
                    END AS MostRecentDate
          FROM      data_table
        ) AS date_query 

另一种使用CASE WHEN的方法

SELECT CASE true 
       WHEN max(row1) >= max(row2) THEN CASE true WHEN max(row1) >= max(row3) THEN max(row1) ELSE max(row3) end ELSE
       CASE true WHEN max(row2) >= max(row3) THEN max(row2) ELSE max(row3) END END
FROM yourTable

DECLARE @TableName TABLE (Number INT, Date1 DATETIME, Date2 DATETIME, Date3 DATETIME, Cost MONEY)

INSERT INTO @TableName 
SELECT 1, '20000101', '20010101','20020101',100 UNION ALL
SELECT 2, '20000101', '19900101','19980101',99 

SELECT Number,
       Cost  ,
       (SELECT MAX([Date])
       FROM    (SELECT Date1 AS [Date]
               UNION ALL
               SELECT Date2
               UNION ALL
               SELECT Date3
               )
               D
       )
       [Most Recent Date]
FROM   @TableName

我不知道它是否在SQL上，等等…在M$ACCESS帮助中，有一个称为MAXA(Value1;Value2;…)的函数，它应该这样做。

希望能帮助到别人。

p.d.:值可以是列或计算值，等等。

SELECT 
    CASE 
        WHEN Date1 >= Date2 AND Date1 >= Date3 THEN Date1 
        WHEN Date2 >= Date3 THEN Date2 
        ELSE Date3
    END AS MostRecentDate 

这样写起来稍微容易一些，因为case语句是按顺序求值的，因此跳过了求值步骤。

Scalar Function cause all sorts of performance issues, so its better to wrap the logic into an Inline Table Valued Function if possible. This is the function I used to replace some User Defined Functions which selected the Min/Max dates from a list of upto ten dates. When tested on my dataset of 1 Million rows the Scalar Function took over 15 minutes before I killed the query the Inline TVF took 1 minute which is the same amount of time as selecting the resultset into a temporary table. To use this call the function from either a subquery in the the SELECT or a CROSS APPLY.

CREATE FUNCTION dbo.Get_Min_Max_Date
(
    @Date1  datetime,
    @Date2  datetime,
    @Date3  datetime,
    @Date4  datetime,
    @Date5  datetime,
    @Date6  datetime,
    @Date7  datetime,
    @Date8  datetime,
    @Date9  datetime,
    @Date10 datetime
)
RETURNS TABLE
AS
RETURN
(
    SELECT      Max(DateValue)  Max_Date,
                Min(DateValue)  Min_Date
    FROM        (
                    VALUES  (@Date1),
                            (@Date2),
                            (@Date3),
                            (@Date4),
                            (@Date5),
                            (@Date6),
                            (@Date7),
                            (@Date8),
                            (@Date9),
                            (@Date10)
                )   AS Dates(DateValue)
)