fileid, dirid UPDATE dualid SET fileid=fileid + 1 UPDATE dualid SET dirid=dirid + 1 UPDATE dualid SET fileid=fileid + 1; SELECT CONCAT('F', fileid) AS fileid FROM dualid; UPDATE dualid SET dirid=dirid + 1; SELECT CONCAT('D', dirid) AS dirid FROM dualid; SELECT CONCAT('F', fileid) AS fileid FROM dualid SELECT CONCAT('D', dirid) AS dirid FROM dualid