Influxdb manipulation

How can i delete unwanted host from my influxdb !
( iwant to delete HAproxy2 from my database)
i tried show series where host =’…’
then DROP SERIES WHERE HOST=’…’
but

drop series where host=‘HAproxy2’

show series where host=‘HAproxy2’
drop series where host=‘HAproxy2’
show series where host=‘HAproxy2’
show series where host=‘HAproxy2’
show series where host=‘HAproxy2’
key

cpu,cpu=cpu-total,host=HAproxy2
cpu,cpu=cpu0,host=HAproxy2
cpu,cpu=cpu1,host=HAproxy2
disk,device=sda1,fstype=ext4,host=HAproxy2,mode=rw,path=/
diskio,host=HAproxy2,name=loop0
diskio,host=HAproxy2,name=loop1
diskio,host=HAproxy2,name=loop2
diskio,host=HAproxy2,name=loop3
diskio,host=HAproxy2,name=loop4
diskio,host=HAproxy2,name=sda
diskio,host=HAproxy2,name=sda1
diskio,host=HAproxy2,name=sda2
diskio,host=HAproxy2,name=sda5
kernel,host=HAproxy2
mem,host=HAproxy2
net,host=HAproxy2,interface=all
processes,host=HAproxy2
swap,host=HAproxy2
system,host=HAproxy2