CREATE TABLE customer_contact_channels (customer_id DECIMAL, channel_code TEXT, active_from_date TIME, active_to_date TIME, contact_number TEXT)
CREATE TABLE customer_orders (order_id DECIMAL, customer_id DECIMAL, order_status TEXT, order_date TIME, order_details TEXT)
CREATE TABLE products (product_id DECIMAL, product_details TEXT)
CREATE TABLE addresses (address_id DECIMAL, address_content TEXT, city TEXT, zip_postcode TEXT, state_province_county TEXT, country TEXT, other_address_details TEXT)
CREATE TABLE order_items (order_id DECIMAL, product_id DECIMAL, order_quantity TEXT)
CREATE TABLE customers (customer_id DECIMAL, payment_method TEXT, customer_name TEXT, date_became_customer TIME, other_customer_details TEXT)
CREATE TABLE customer_addresses (customer_id DECIMAL, address_id DECIMAL, date_address_from TIME, address_type TEXT, date_address_to TIME)

What is the 'active to date' of the latest contact channel used by 'Tillman Ernser'?
SELECT MAX(t2.active_to_date) FROM customers AS t1 JOIN customer_contact_channels AS t2 ON t1.customer_id = t2.customer_id WHERE t1.customer_name = "Tillman Ernser"
SELECT MAX("t2"."active_to_date") FROM "customers" AS "t1" JOIN "customer_contact_channels" AS "t2" ON "t1"."customer_id" = "t2"."customer_id" WHERE "Tillman Ernser" = "t1"."customer_name"