/* Insert the data into customer_links */
INSERT INTO customer_links (hiretrack_id, magento_id, myob_uid, setmore_key)
VALUES ('{hiretrack_id}', '{magento_id}', '{myob_uid}', '{setmore_key}')

/* Update the entry if a duplicate key is found */
ON DUPLICATE KEY UPDATE
    magento_id = VALUES(magento_id),
    myob_uid = VALUES(myob_uid),
    setmore_key = VALUES(setmore_key);