SELECT DISTINCT channel_code FROM customers AS t1 JOIN customer_contact_channels AS t2 ON t1.customer_id  =  t2.customer_id WHERE t1.customer_name  =  "Tillman Ernser"
Which contact channel has been used by the customer with name "Tillman Ernser"?
SELECT DISTINCT channel_code FROM customers AS t1 JOIN customer_contact_channels AS t2 ON t1.customer_id = t2.customer_id WHERE t1.customer_name = `` Tillman Ernser ''
select distinct channel_code from customers as t1 join customer_contact_channels as t2 on t1 . customer_id = t2 . customer_id where t1 . customer_name = value
Which contact channel has been used by the customer with name `` Tillman Ernser '' ?