Dfyjkt

I have a system making third party API request to another server. But i want to make sure the user doesn't request again within the next 15 minutes of the first request. So I check time difference in below method which is not working correctly,

ROUND(sysdate - d.CREATE_DATE,2) as PASSED_TIME

Here d.CREATE_DATE is also saved by using SYSDATE keyword when the first request is sent. I get a number out put but it doesn't seem to be right.
So I want to know how can i take time difference in minutes

For oracle, it is enough to just subtract the dates if the field "CREATE_DATE" is "date" datatype and multiply by 24*60 to get the difference in minutes.
Eg:

select to_char(sysdate-15/24/60,'dd-mon-yyyy hh24:mi:ss') as first_request /*15 minutes back*/
 ,to_char(sysdate,'dd-mon-yyyy hh24:mi:ss') as current_request
 ,(sysdate - sysdate +15/24/60)*24*60 as diff_in_minutes
 from dual

One option would be recording and comparing to SYSTIMESTAMP:

SELECT
 EXTRACT (day FROM ts) * 24*60 +
 EXTRACT (hour FROM ts) * 60 +
 EXTRACT (minute FROM ts) AS PASSED_TIME
FROM
(
 SELECT SYSTIMESTAMP - CREATE_TS ts
 FROM yourTable
) t;

This answer assumes that the CREATE_TS column stores the incoming timestamps, using SYSTIMESTAMP as the incoming value.