sql - 将日期时间转换为 Unix 时间戳

Question

在 Microsoft SQL Server 2012 或更高版本中，是否可以在单个 select 语句中将日期时间值转换为 Unix 时间戳？如果是这样，怎么做？

Answer 1

正如 Peter Halasz 在 T-SQL DateTime to Unix Timestamp 中提到的那样:

Converting a datetime to unix timestamp is easy, but involves error prone typing the following:

@timestamp=DATEDIFF(second,{d '1970-01-01'},@datetime)

Where @datetime is the datetime value you want to convert. The {d ‘yyyy-mm-dd’} notation is an ODBC escape sequence.

The function:

CREATE FUNCTION UNIX_TIMESTAMP (
@ctimestamp datetime
)
RETURNS integer
AS
BEGIN
  /* Function body */
  declare @return integer
   
  SELECT @return = DATEDIFF(SECOND,{d '1970-01-01'}, @ctimestamp)
   
  return @return
END

立即尝试如下@O A:

SELECT UNIX_TIMESTAMP(GETDATE());