Table schema:
CREATE TABLE order_items (product_id VARCHAR, order_id VARCHAR); CREATE TABLE orders (order_id VARCHAR, date_order_placed VARCHAR)

Question: Give me a list of distinct product ids from orders placed between 1975-01-01 and 1976-01-01?
SQL: SELECT DISTINCT T2.product_id FROM orders AS T1 JOIN order_items AS T2 ON T1.order_id = T2.order_id WHERE T1.date_order_placed >= "1975-01-01" AND T1.date_order_placed <= "1976-01-01"