select * from data where sn='12250' order by id desc limit 4
idsntspqvaluesystemts
20703539 12250 ts 1558464902 1558464902 Tue 21 05 2019 20:55:02
20703538 12250 temp 24.69 1558464902 Tue 21 05 2019 20:55:02
20703365 12250 ts 1558464602 1558464602 Tue 21 05 2019 20:50:02
20703364 12250 temp 24.69 1558464602 Tue 21 05 2019 20:50:02

Tue May 21 20:58:25 2019 by walley