datedif to year-month-day.sql

CREATE FUNCTION get_Exact_Date_diff(@date SMALLDATETIME,@date2 SMALLDATETIME)
 returns VARCHAR(50)

    AS

    BEGIN

    DECLARE @date3 SMALLDATETIME

    DECLARE @month INT,@year INT,@day INT

    IF @date>@date2
     BEGIN
        SET @date3=@date2
        SET @date2=@date
        SET @date=@date3
    END



    SELECT @month=datediff (MONTH,@date,@date2)

    IF dateadd(month,@month,@date) >@date2
    BEGIN
        SET @month=@month-1
    END
    SET @day=DATEDIFF(day,dateadd(month,@month,@date),@date2)

    SET @year=@month/12
    SET @month=@month % 12

    RETURN (CASE WHEN @year=0 THEN '' WHEN @year=1 THEN CONVERT(VARCHAR(50),@year ) + ' year ' WHEN @year>1 THEN CONVERT(VARCHAR(50),@year ) + ' years ' END)
    + (CASE WHEN @month=0 THEN '' WHEN @month=1 THEN CONVERT(VARCHAR(50),@month ) + ' month ' WHEN @month>1 THEN CONVERT(VARCHAR(50),@month ) + ' months ' END)
    + (CASE WHEN @day=0 THEN '' WHEN @day=1 THEN CONVERT(VARCHAR(50),@day ) + ' day ' WHEN @day>1 THEN CONVERT(VARCHAR(50),@day ) + ' days ' END)

END