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 products (product_id VARCHAR); CREATE TABLE Order_items (product_id VARCHAR)
### Question:
How many products were not included in any order?
### Answer:
SELECT COUNT(*) FROM products WHERE NOT product_id IN (SELECT product_id FROM Order_items)