ms sql server中实现的unix时间戳函数（含生成和格式化，可以和mysql兼容）

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


CREATE FUNCTION from_unixtime (@ts integer) RETURNS datetime 
AS
BEGIN
 /* Function body */
 declare @return datetime
 select @return = DATEADD(second, @ts, {d 1970-01-01})
 return @return
END

select dbo.UNIX_TIMESTAMP(2013-1-1)
select dbo.from_unixtime(2145000000)