Getting derived column from database | SQL query | DB2 SystemDate - sql

Question

My table is PRODUCTINFO:
Column name : product_name | launch_date
Sample Date : product1 2017-01-20
I need a SQL query to decide if the product is newly launched or not.
Business rule :
if (launch_date - currentdate < 0 && currentdate - launch_date < 90)
newly_launched = 'YES'
else
newly_launched = 'NO'
where currentdate is today's date.
SQL query I am witting is like :
SELECT launch_date, X as newly_launched
FROM PRODUCTINFO
WHERE product_name = 'product1'
I am not able to figure out correct replacement of 'X' in my query for desired result.
Problem I am facing is using currentdate and if else block in my query
Please help.
One way to get currentdate in DB2 using following query :
SELECT VARCHAR_FORMAT(CURRENT TIMESTAMP, 'YYYYMMDD')
FROM SYSIBM.SYSDUMMY1
Still not sure how to use this with my if else scenario.
Answer here don't solve my problem as this scenario is if-else based.

Answer 1

use TIMESTAMPDIFF with 16 as first parameter for count number days between 2 timestamps, for more detail look here
try this
select launch_date,
case when TIMESTAMPDIFF( 16, cast(cast(launch_date as timestamp) - current timestamp as char(22))) >0 and
TIMESTAMPDIFF( 16, cast(cast(launch_date as timestamp) - current timestamp as char(22))) <90 then 'YES' else 'NO' end newly
from PRODUCTINFO
WHERE product_name = 'product1'

Answer 2

simply use datediff function in a case syntax, I hope it could help!
SELECT launch_date,
case
when DATEDIFF(day,launch_date,getdate()) BETWEEN 0 AND 90 then 'YES'
else 'NO'
end AS newly_launched
FROM PRODUCTINFO
WHERE product_name = 'product1'
in case you want to do it for all your records:
SELECT launch_date,
case
when DATEDIFF(day,launch_date,getdate()) BETWEEN 0 AND 90 then 'YES'
else 'NO'
end AS newly_launched
FROM PRODUCTINFO