你如何从现有表中调用最新日期？

Question

我有一张名为tbl.date的表，我有一个列LAST_UPDATE。我需要获取最新的更新日期。这是我到目前为止：

SELECT *
FROM [tbl.date]
WHERE [LAST_UPDATE] = --I need an SQL system code to go in here to fetch the latest update date

Answer 1

如果您使用的是SQL Server，并且LAST_UPDATE列是Date类型

SELECT * FROM tbl.date
WHERE LAST_UPDATE = (SELECT MAX(LAST_UPDATE) FROM tbl.date)

Answer 2

我只会SELECT TOP 1然后ORDER BY DESC

SELECT TOP 1 *
FROM [tbl.date]
ORDER BY [LAST_UPDATE] DESC

要么

SELECT MAX(LAST_UPDATE) AS LastUpdate
FROM [tbl.date]

要么

SELECT [LAST_UPDATE]
FROM [tbl.date]
ORDER BY [LAST_UPDATE] DESC
LIMIT 1;

Answer 3

另一种方法，使用TOP WITH TIES：

SELECT TOP (1) WITH TIES *
    FROM  tbl.date
    ORDER BY [LAST_UPDATE] DESC;

它返回表中与最新更新日期匹配的所有记录。