get sum

[sql]

I have comp 1, comp2, hall 1 , hall2 , processStatus in table and inside processStatus colum I have valew a, b, c , aand b = successful and c = failed
how can I get sum(successful) sum(failed) group by comp1, comp2, hall1, hall2
Thank you!
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Lincoln ls history

[skhanal]

select comp1, comp2, hall1, hall2 ,sum(case processstatus when 'successful' then 1 else 0 end case),
sum(case processstatus when 'failed' then 1 else 0 end case),
from t1
group by comp1, comp2, hall1, hall2