select * from data where sn='ds1' order by id desc limit 4
idsntspqvaluesystemts
29378711 ds1 temp 14.00 1576443957 Sun 15 12 2019 22:05:57
29378694 ds1 temp 14.00 1576443934 Sun 15 12 2019 22:05:34
29378682 ds1 temp 14.00 1576443912 Sun 15 12 2019 22:05:12
29378670 ds1 temp 14.00 1576443890 Sun 15 12 2019 22:04:50

Sun Dec 15 22:06:06 2019 by walley