SQL Server 自定义函数返回时间或时间戳

自定义函数返回时间或时间戳

CREATE FUNCTION [dbo].[DateAndTimestamp]
(@date as datetime,
@timestamp as int,
@retType as varchar(10)
)
RETURNS varchar(100) AS  
BEGIN 
	declare @datestring as varchar(100)
	if @retType='dtime'
	begin
		set @datestring=(SELECT FORMAT(@date, 'yyyy-MM-dd HH:mm:ss.fff'))
	end
	else
	begin
		set @datestring=(SELECT DATEDIFF(S,'1970-01-01 00:00:00', (SELECT FORMAT(@date, 'yyyy-MM-dd HH:mm:ss.fff'))));
	end
	return @datestring
END