MSSQL：服务器之间关于日期转换的差异

Question

我有这个脚本：

SELECT UserID, 
       CONVERT(SmallDateTime, cast([1]  + '/' + [2] + '/' + [3] as varchar)) as ReleaseDate, 
       ChannelID
FROM
(
SELECT RU.UserID, U.FieldID,  RU.ChannelID, U.AnswerText
FROM dbo.Users U WITH (NOLOCK) INNER JOIN dbo.ResourceUsers RU WITH (NOLOCK)
      ON U.UserID = RU.UserID
WHERE  (FieldID = 1 -- release day
          OR FieldID = 2 -- release month
          OR FieldID = 3) 
) AS P
PIVOT 
(
      MAX(AnswerText) FOR FieldID in ([1], [2], [3])
) AS pvt

同样的脚本在服务器上完美运行。在其他服务器上，我收到此错误：

Msg 295, Level 16, State 3, Line 3 Conversion failed when converting character string to smalldatetime data type.

为什么？有什么不同？这些表在两台服务器上具有相同的结构。

Answer 1

在 sql 服务器 2012+ 中你可以使用 datefromparts

SELECT UserID, 
       convert(smalldatetime,datefromparts([3],[2],[1])) as ReleaseDate, 
       ChannelID
FROM ....

在 sql 服务器 2012 之前，您可以创建 'yyyyMMdd' 格式的字符串

SELECT UserID, 
       convert(smalldatetime,
          convert(char(4),[3])
        + right('0'+convert(varchar(3),[2]),2)
        + right('0'+convert(varchar(3),[1]),2)
        ) as ReleaseDate, 
       ChannelID
FROM ....

MSSQL：服务器之间关于日期转换的差异

MSSQL: difference between servers regarding date conversion

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