Case statement with datedfif and between

Question

I am using Sybase IQ, and have the following SQL code which doesn't seem to work. The issue is with the case statement.. Thanks in advance

SELECT  a.cusid, start_date, effective_dt, 
case when DATEDIFF(DAY, start_date, effective_dt) >= 5476 THEN 'Green'
case when DATEDIFF(DAY, start_date, effective_dt) between 2921 AND 4575 THEN 'Red'
case when DATEDIFF(DAY, start_date, effective_dt) BETWEEN 1096  AND 2920 THEN 'Blue'
case when DATEDIFF(DAY, start_date, effective_dt) BETWEEN 0 AND 1095 THEN 'Rose'
ELSE NULL END as tier
FROM   tablea a
INNER JOIN tableb b
    ON a.cusid = b.cusid
WHERE   b.active = 'Yes' 

Answer 1

No need to have case keyword each time with when clause. Try this :

SELECT  a.cusid, start_date, effective_dt, 
case when DATEDIFF(DAY, start_date, effective_dt) >= 5476 THEN 'Green'
when DATEDIFF(DAY, start_date, effective_dt) between 2921 AND 4575 THEN 'Red'
when DATEDIFF(DAY, start_date, effective_dt) BETWEEN 1096  AND 2920 THEN 'Blue'
when DATEDIFF(DAY, start_date, effective_dt) BETWEEN 0 AND 1095 THEN 'Rose'
ELSE NULL END as tier
FROM   tablea a
INNER JOIN tableb b
    ON a.cusid = b.cusid
WHERE   b.active = 'Yes'