oracle - How do a repeat a query for past 30 days without union 30 times? -

i have query returns value today (sysdate) best way repeat query past 30 days without creating 30 separate queries unioned together?

for example here basic query:

select sum(duration)/3600 ign_oee_events_d  asset_id = 1978 , event_type = 1 , shift = 2 , trunc(event_dt)=trunc(sysdate) 

what avoid repeating query this:

select sum(duration)/3600 ign_oee_events_d  asset_id = 1978 , event_type = 1 , shift = 2 , trunc(event_dt)=trunc(sysdate) union select sum(duration)/3600 ign_oee_events_d  asset_id = 1978 , event_type = 1 , shift = 2 , trunc(event_dt)=trunc(sysdate)-1 union select sum(duration)/3600 ign_oee_events_d  asset_id = 1978 , event_type = 1 , shift = 2 , trunc(event_dt)=trunc(sysdate)-2 union select sum(duration)/3600 ign_oee_events_d  asset_id = 1978 , event_type = 1 , shift = 2 , trunc(event_dt)=trunc(sysdate)-3 

is there way this?

repeat dates event_dt between sysdate , sysdate -30 select sum(duration)/3600 ign_oee_events_d  asset_id = 1978 , event_type = 1 , shift = 2  

thank you.

it sounds need group by. i'm guessing want order by

select trunc(event_dt), sum(duration)/3600   ign_oee_events_d   asset_id = 1978     , event_type = 1     , shift = 2     , trunc(event_dt) >= trunc(sysdate)-30  group trunc(event_dt)  order trunc(event_dt)