select * from data where sn='221' and pq='hum' order by id desc limit 4
idsntspqvaluesystemts
27168269 221 hum 44.50 1571485046 Sat 19 10 2019 13:37:26
27168259 221 hum 45.10 1571485026 Sat 19 10 2019 13:37:06
27168253 221 hum 45.10 1571485025 Sat 19 10 2019 13:37:05
27168246 221 hum 45.00 1571485006 Sat 19 10 2019 13:36:46

Mon Oct 21 04:03:36 2019 by walley