Question

我有一张年，月，日的表格如下。

Year      Month Day
2015      10    28
2015      10    29
2015      10    29
2015      10    30
2015      10    30
2015      10    30
2015      11    4
2015      11    5
2015      11    9
2015      11    19
2016      1     31
2016      4     1

我希望获得当年最高年份和相应的最高月份以及当年，月份列的日期

输出：

2016 4 1

如果表格不包含 2016 1 31 2016 4 1

输出的行 2015 11 19

Answer 1

DECLARE @temp TABLE
(
    Y SMALLINT,
    M TINYINT,
    D TINYINT,
    PRIMARY KEY CLUSTERED (Y DESC, M DESC, D DESC) WITH(IGNORE_DUP_KEY=ON)
)

INSERT INTO @temp (Y, M, D)
VALUES
    (2015, 10, 28), (2015, 10, 29),
    (2015, 10, 29), (2015, 10, 30),
    (2015, 10, 30), (2015, 10, 30),
    (2015, 11, 4 ), (2015, 11, 5 ),
    (2015, 11, 9 ), (2015, 11, 19),
    (2016, 1 , 31), (2016, 4 , 1 )

SELECT TOP(1) *
FROM @temp
ORDER BY Y DESC, M DESC, D DESC

结果 -

Y      M    D
------ ---- ----
2016   4    1

Answer 2

您可以在sql中使用max函数。

SELECT max(Year) as Year, Month, Day FROM table_name.

希望这有帮助！

Answer 3

检查此示例。

DECLARE @temp TABLE
(
    Y SMALLINT,
    M TINYINT,
    D TINYINT,
    PRIMARY KEY CLUSTERED (Y DESC, M DESC, D DESC) WITH(IGNORE_DUP_KEY=ON)
)

INSERT INTO @temp (Y, M, D)
VALUES
    (2015, 10, 28), (2015, 10, 29),
    (2015, 10, 29), (2015, 10, 30),
    (2015, 10, 30), (2015, 10, 30),
    (2015, 11, 4 ), (2015, 11, 5 ),
    (2015, 11, 9 ), (2015, 11, 19),
    (2016, 1 , 31), (2016, 4 , 1 )

; with cte as
(
    select cast ( cast (y as varchar(15)) +'-' + cast (m as varchar(15)) + '-' + cast (m as varchar(15)) as date) dt , y , m, d
    from @temp
)
select top 1 y,m,d from cte order by dt desc

delete @temp where y = '2016' 

; with cte as
(
    select cast ( cast (y as varchar(15)) +'-' + cast (m as varchar(15)) + '-' + cast (m as varchar(15)) as date) dt , y , m, d
    from @temp
)
select top 1 y,m,d from cte order by dt desc

Answer 4

如果您确定这些值代表有效日期，您可以将它们转换为日期并获得MAX：

SELECT DATEPART(year, MAX(CAST(Y as varchar(4)) + RIGHT('0' + CAST(M AS varchar(2)), 2) + RIGHT('0' + CAST(D AS varchar(2)), 2))),
    DATEPART(month, MAX(CAST(Y as varchar(4)) + RIGHT('0' + CAST(M AS varchar(2)), 2) + RIGHT('0' + CAST(D AS varchar(2)), 2))),
    DATEPART(dd, MAX(CAST(Y as varchar(4)) + RIGHT('0' + CAST(M AS varchar(2)), 2) + RIGHT('0' + CAST(D AS varchar(2)), 2)))
FROM @temp

Answer 5

这是查询（替换你的表名）

SELECT TOP 1 YEAR, MONTH, DAY  
FROM YOUR_TABLE
ORDER BY YEAR DESC, MONTH DESC, DAY DESC

如何使用sql获取最大列？

5 个答案: