CREATE TABLE device (device_id NUMBER, device CLOB, carrier CLOB, package_version CLOB, applications CLOB, software_platform CLOB)
CREATE TABLE shop (shop_id NUMBER, shop_name CLOB, location CLOB, open_date CLOB, open_year NUMBER)
CREATE TABLE stock (shop_id NUMBER, device_id NUMBER, quantity NUMBER)

What is the average quantity of stocks?
SELECT AVG(quantity) FROM stock
SELECT AVG("quantity") FROM "stock"