select * from data where sn='ds1' and pq='temp' order by id desc limit 4
idsntspqvaluesystemts
18878263 ds1 temp 12.63 1553492851 Mon 25 03 2019 06:47:31
18878250 ds1 temp 12.63 1553492809 Mon 25 03 2019 06:46:49
18878239 ds1 temp 12.63 1553492787 Mon 25 03 2019 06:46:27
18878223 ds1 temp 12.63 1553492765 Mon 25 03 2019 06:46:05

Mon Mar 25 06:47:34 2019 by walley