select * from data where sn='ds1' and pq='temp' order by id desc limit 4
idsntspqvaluesystemts
20704283 ds1 temp 15.06 1558466156 Tue 21 05 2019 21:15:56
20704262 ds1 temp 15.06 1558466135 Tue 21 05 2019 21:15:35
20704251 ds1 temp 15.06 1558466113 Tue 21 05 2019 21:15:13
20704238 ds1 temp 15.06 1558466091 Tue 21 05 2019 21:14:51

Tue May 21 21:16:07 2019 by walley