Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE customer_contact_channels ( customer_id VARCHAR )
TABLE: CREATE TABLE customers ( customer_id VARCHAR, customer_name VARCHAR )

### Question ###
Which contact channel has been used by the customer with name 'Tillman Ernser'?

### Accurate SQL ###

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"