劳而无功

to work hard while accomplishing little / to toil to no avail

and / as well as / and so / but (not) / yet (not) / (indicates causal relation) / (indicates change of state) / (indicates contrast)

not to have / no / none / not / to lack / un- / -less

to toil / labor / laborer / to put sb to trouble (of doing sth) / meritorious deed / to console (Taiwan pr. [lao4] for this sense)

meritorious deed or service / achievement / result / service / accomplishment / work (physics)