Table schema:
CREATE TABLE shipments (order_id VARCHAR, shipment_tracking_number VARCHAR); CREATE TABLE orders (date_order_placed VARCHAR, order_id VARCHAR)

Question: When was the order placed whose shipment tracking number is 3452? Give me the date.
SQL: SELECT T1.date_order_placed FROM orders AS T1 JOIN shipments AS T2 ON T1.order_id = T2.order_id WHERE T2.shipment_tracking_number = 3452