Want specific years between date joined and now - sql

Question

I am trying to get the members of a company that qualify for 'EMERITUS' status.
To qualify, one must be a member for 35 years from the date joined 'JOIN_DATE' and must be >=65 years of age to qualify 'BIRTH_DATE'. I want to see >= 2015 under the 'EMERITUS' column. Does this query make sense?
SELECT
N.ID, N.FULL_NAME, N.MEMBER_TYPE,
N.JOIN_DATE,DA.BIRTH_DATE,
(SELECT CASE
WHEN DATEDIFF(YEAR,N.JOIN_DATE,GETDATE()) + 35 > DATEDIFF(YEAR,DA.BIRTH_DATE,GETDATE()) + 65
THEN CONVERT(VARCHAR(4),YEAR(N.JOIN_DATE) + 35)
WHEN DATEDIFF(YEAR,N.JOIN_DATE,GETDATE()) + 35 < DATEDIFF(YEAR,DA.BIRTH_DATE,GETDATE()) + 65
THEN CONVERT(VARCHAR(4),YEAR(DA.BIRTH_DATE) + 65)
ELSE NULL
END) AS 'EMERITUS'

Answer 1

Based upon the comments above it looks like you are on the right track.
Using the below SQL (with example in SQLFiddle listed) you should be able to get the year they will be EMERITUS and the number of years until EMERITUS.
select N_sub.*
,case when DATEDIFF(d,GETDATE(),N_sub.EMERITUS)/365.0 > 0
then DATEDIFF(d,GETDATE(),N_sub.EMERITUS)/365.0
else 0
end YEARS_UNTIL_EMERITUS
from(select N."ID"
,N.FULL_NAME
,N.MEMBER_TYPE
,N.JOIN_DATE
,N.BIRTH_DATE
, (select case
when DATEDIFF (d,N.JOIN_DATE, GETDATE ())/365 + 35 > DATEDIFF(d,N.BIRTH_DATE, GETDATE ())/365 + 65
then CONVERT(VARCHAR(10),DATEADD(year,35,N.BIRTH_DATE),110)
when DATEDIFF (d,N.JOIN_DATE, GETDATE ())/365 + 35 < DATEDIFF(d,N.BIRTH_DATE, GETDATE ())/365 + 65
then CONVERT(VARCHAR(10),DATEADD(year,65,N.BIRTH_DATE),110)
else null
end) AS 'EMERITUS'
from N
) N_sub
SQL Fiddle: http://sqlfiddle.com/#!6/e464cc/7
With this query it is a bit better than just raw comparing the years as it goes by # of days divided by 365. Logic could be added to account for leap years. The results will show the date they get Emeritus and the number of years until they would get it. 0 if == 0 or negative.