Funcion de SQL que permite convertir una fecha (historica) en tiempo transcurrido Hace 1 segundo/minuto/hora/dia/mes/año

GetLastActiveDateTime.sql

CREATE FUNCTION GetLastActiveDateTime
(
	@lastActiveDate Datetime
)
RETURNS varchar(30)
AS
BEGIN
  DECLARE @LastActivity varchar(100)
  SET @LastActivity = '';
  DECLARE @today datetime, @nowLastActiveDate datetime
  DECLARE @years int, @months int, @days int, @hours int, 
  @minutes int, @seconds int, @h int, @m int, @s int  
  
  SELECT @today = GETDATE() 
  SELECT @nowLastActiveDate = DATEADD(year, 
  DATEDIFF(year, @lastActiveDate, @today), @lastActiveDate)            
  
  SELECT @years = DATEDIFF(year, @lastActiveDate, @today) - 
  (CASE WHEN @nowLastActiveDate > @today THEN 1 ELSE 0 END) 
  SELECT @months = MONTH(@today - @nowLastActiveDate) - 1 
  SELECT @days = DAY(@today - @nowLastActiveDate) - 1 
  
  SELECT @h = DATEDIFF(HOUR, @lastActiveDate, @today)
  SELECT @m = DATEDIFF(MINUTE, @lastActiveDate, @today)
  SELECT @s = DATEDIFF(SECOND, @lastActiveDate, @today)
  
  SET @hours = (@h%24)
  SET @minutes = (@m%60)
  SET @seconds = (@s%60)                 
      
	  
SET @LastActivity =
	(CASE 
		WHEN @years = 1 THEN ' 1 año
		(' +  convert(varchar, @lastActiveDate, 105) + ')'
		WHEN @years > 1 THEN convert(varchar(3),@years) + 
		' años (' +  convert(varchar, @lastActiveDate, 105) + ')'
		WHEN @months > 1 THEN ' 1 mes (' +  convert(varchar, @lastActiveDate, 105) + ')'
		WHEN @months = 1 THEN convert(varchar(3),@months) + 
		' meses (' +  convert(varchar, @lastActiveDate, 105) + ')'
		WHEN @days = 1 THEN ' 1 dia (' +  convert(varchar, @lastActiveDate, 105) + ')'
		WHEN @days > 1 THEN convert(varchar(3),@days) + 
		' días (' +  convert(varchar, @lastActiveDate, 105) + ')'
		WHEN @hours = 1 THEN ' 1 hora '
		WHEN @hours > 1 THEN convert(varchar(3),@hours) + ' horas '
		WHEN @minutes = 1 THEN ' 1 minuto '
		WHEN @minutes > 1 THEN convert(varchar(3),@minutes) + ' minutos '
		WHEN @seconds = 1 THEN ' 1 segundo '
		WHEN @seconds > 1 THEN convert(varchar(3),@seconds) + ' segundos'
		ELSE convert(varchar, @lastActiveDate, 105)
	 END)
			 
	 RETURN 'Hace ' + @LastActivity; 
END