problem with joining two tables

hi, i've got this problem:
i have to manage a list of events in my city, publishing them into my web
site; each event has a 'content' (containing infos such as title, place,
description, etc..) and is linked to one or more dates. I I decided to
create 2 tables, one to store the 'content' (which has a unique id), the
other to store the dates of the events; i called the first table 'real_time'
and the second 'real_time_ts': each two has the filed 'id_real_time' which
is used to correlate the 'contents' with the 'dates'. Everything is going
well, but when a content has more than one 'date' i get the same content
repeated for the number of its dates... this is not what i want to retrieve
! i want to do a SELECT which gives me only one occurance for each content,
even when the content has more than one date of happening ! I tried
grouping, joining a.s.o. but i came to nothing... can anyone please help me
? i really can't get out of this :-(

the sql I'm using is:

select t.id_realtime, t.id_real_users, t.id_places, t.id_index,
t.content, t.shown_place, t.titol,
s.start_date, s.end_date, s.start_time, s.end_time
from real_time t, real_time_ts s
where
t.id_index = <dtml-sqlvar real_time.id_index type="nb">
and
t.id_real_time = s.id_real_time
and
( s.start_date >= <dtml-sqlvar now type="string">
or
s.end_date >= <dtml-sqlvar now type="string"> )
and
t.prio = '1'
order by s.start_date, s.end_date

being "now" the current date given by ZopeTime().strftime('%Y-%m-%d')

tnx to anyone who has read my e-mail and would (eventually!) help me !

have a nice day,
Giorgio A.