SELECT channel_code FROM customer_contact_channels GROUP BY channel_code HAVING count(customer_id)  <  5
Which contact channel codes were used less than 5 times?
SELECT channel_code FROM customer_contact_channels GROUP BY channel_code HAVING count ( customer_id ) < 5
select channel_code from customer_contact_channels group by channel_code having count ( customer_id ) < value
Which contact channel codes were used less than 5 times ?