author as users,

count(*) as no_txn

FROM near.beta.github_activity

group by 1)

case

when no_txn=1 then 'a. Just 1 time'

when no_txn>1 and no_txn<=5 then 'b. 2-5 times'

when no_txn>5 and no_txn<=20 then 'c. 5-20 times'

when no_txn>20 then 'd. Over 20 times'

end as gp,

count(distinct users) as no_users

from t1

group by 1