SELECT
    item.PRODUCT_ID AS "ID",
    (SELECT PRODUCT_NAME FROM OEHR_PRODUCT_INFORMATION info WHERE info.PRODUCT_ID = item.PRODUCT_ID) AS "Product",
    (SELECT COUNT( * ) FROM OEHR_ORDER_ITEMS tmp WHERE item.PRODUCT_ID = tmp.PRODUCT_ID) AS "Number of Orders",
    SUM(item.QUANTITY) AS "Quantity",
    (SUM(item.QUANTITY) * (SELECT LIST_PRICE FROM OEHR_PRODUCT_INFORMATION info2 WHERE info2.PRODUCT_ID = item.PRODUCT_ID)) AS "Turnover"
FROM
    OEHR_ORDER_ITEMS item
GROUP BY item.PRODUCT_ID