select * from data where sn='12250' order by id desc limit 4
idsntspqvaluesystemts
18877648 12250 ts 1553491802 1553491802 Mon 25 03 2019 06:30:02
18877647 12250 temp 24.56 1553491802 Mon 25 03 2019 06:30:02
18877476 12250 ts 1553491502 1553491502 Mon 25 03 2019 06:25:02
18877475 12250 temp 24.56 1553491502 Mon 25 03 2019 06:25:02

Mon Mar 25 06:34:04 2019 by walley