SQL QUERY to find the all senior citizen from table-CodePudding

select * from patient where age as datediff(pdob,'2022-06-11')>=75;

why is this query is giving an empty set?

My question is:- Find all the patients who can avail of senior citizen discount.

CodePudding user response：

The problem of DATE_DIFF is that it outputs the difference in days. If you want a difference in years, you can use DATE_ADD:

SELECT * 
FROM patient 
WHERE DATE_ADD(pdob, INTERVAL 75 YEAR) < '2022-06-11'

Check the demo here.

Note: if you really want to use DATE_DIFF, you need to transform 75 years into days and use that value.