check for duplicate data before insert

Question

I\'m creating a java swing program where users can create a record, but I want to be able to check for duplicates before allowing the users to create the record. Here\'s my

Answer 1

If you want DutyName and volNric to have unique values, then do so with a unique constraint/index:

create index idx_assignrequests_dutyname_volnric on assignrequests(dutyname, volnric);

Then, when you do the insert, you can let it fail. Or, you can just ignore it using on duplicate key update:

INSERT into assignrequests(reqId, dutyName, volNric)"
    VALUES ('" + id + "','" + dutyName + "','" + volNric + "')
    ON DUPLICATE KEY UPDATE dutyName = VALUES(dutyName);

The column being updated is being set to itself -- so the operation doesn't do anything.