select * from data where sn='ds1' order by id desc limit 4
idsntspqvaluesystemts
18877603 ds1 temp 12.63 1553491727 Mon 25 03 2019 06:28:47
18877595 ds1 temp 12.63 1553491706 Mon 25 03 2019 06:28:26
18877579 ds1 temp 12.63 1553491684 Mon 25 03 2019 06:28:04
18877568 ds1 temp 12.63 1553491663 Mon 25 03 2019 06:27:43

Mon Mar 25 06:29:06 2019 by walley