I am hoping to generate unique contact %. not sure how to divide the 2. Can someone help? thanks

select
attached to_,
count(record),
count(distinct customer),
from table
group by 1

table of sample data

CodePudding user response：

Try the following:

Select attached_to,
       COUNT(customer) As total_contact,
       COUNT(Distinct customer) As unique_contact,
       COUNT(Distinct customer) / COUNT(customer) As '%_of_unique'
From Tbl
Group By attached_to

See a demo from db<>fiddle.