Query to pull transactions where dispute date exceeds payment date by 120 days

Super new with SQL and just was wanting a nudge in the right direction I have a payment table with column a) payment date and column b) dispute date. I want to pull all transactions where the dispute date exceeds the payment date by 120 days. I think it should have something to do with a CASE function but again super new to this!

SELECT merch_ref, payment_method, payment_date, dispute_date 
CASE WHEN dispute_date > (payment_date,120 dd) 
THEN 'NotLegit'
ELSE LEGIT
END 
FROM payment_table

This is my first question and was slightly anxious as I know there is a format that you guys like so, any hints and tips on how to improve my structure of questioning would also be super helpful. On ORACLE

Answer

I want to pull all transactions where the dispute date exceeds the payment date by 120 days. I think it should have something to do with a CASE function but again super new to this!

What you are describing sounds more like filtering, which is WHERE, not CASE:

SELECT merch_ref, payment_method, payment_date, dispute_date 
FROM payment_table
WHERE disputer_date > payment_date + interval '120' day;

You would use a CASE expression to return a new column on each row, but (without a WHERE) all rows would be returned, not just the ones meeting your condition.