[exim] lookup result

hi,
when a sql-lookup returns more than one result-row each containing a
system-user-name
(i.e local_part=all what is a group, an message shall be send to users
peter,paul and mary .. )

router:
driver = redirect
data = ${lookup mysql{}}
transport = tlocal

the transport is called once for each result-row ?

how can i fake that data when i want to test, how can i do this with
simple file lookup ?

data = peter : paul : mary
or
data = 'peter\npaul\nmary'
or
data = 'peter\0paul\0mary'
?