text: Below is an context that describes a sql query, paired with an question that provides further information. Write an answer that appropriately completes the request.  # noqa: E501
  ### Context:
  CREATE TABLE customers (customer_id VARCHAR); CREATE TABLE customer_events (customer_id VARCHAR)
  ### Question:
  How many customers did not have any event?
  ### Answer:
  SELECT COUNT(*) FROM customers WHERE NOT customer_id IN (SELECT customer_id FROM customer_events)