select * from data where sn='221' and pq='temp' order by id desc limit 4
idsntspqvaluesystemts
22759262 221 temp 21.10 1563674616 Sun 21 07 2019 04:03:36
22759257 221 temp 21.10 1563674615 Sun 21 07 2019 04:03:35
22759249 221 temp 21.10 1563674602 Sun 21 07 2019 04:03:22
22759234 221 temp 21.10 1563674556 Sun 21 07 2019 04:02:36

Sun Jul 21 04:03:45 2019 by walley