SQL Server标量值函数：datetime转为tick

create function getTicks(@time datetime) returns bigint
as
begin
	declare @mintime datetime, @today datetime
	declare @days bigint, @milliseconds bigint
	declare @ticks bigint

	select @mintime='1753-01-01', @today=dateadd(day,datediff(day,0,@time),0)
	--0001-01-01和1753-01-01相差639905天
	select @days=datediff(day,@mintime,@today)+639905, @milliseconds=datediff(millisecond,@today,@time)
	select @ticks=(@days*24*60*60*1000 + @milliseconds)*10000

	return @ticks
end
go