单项选择题产品(PRODUCT)表的结构如下: PRODUCT PRODUCT_ID NUMBER NOT NULL, Primary Key PRODUCT_NAME VARCHAR2(25) SUPPLIER_ID NUMBER Foreign key to SUPPLIER_ID of the SUPPLIER table LIST_PRICE NUMBER(7, 2) COST NUMBER(7, 2) QTY_IN_STOCK NUMBER QTY_ON_ORDER NUMBER REORDER_LEVEL NUMBER REORDER_QTY NUMBER 如果使用如下的SQL语句,哪个子句将会产生错误 SELECT supplier_id,AVG(cost) FROM product WHERE AVG(list_price)>60.00 GROUP BY supplier_id ORDER BY AVG(cost)DESC;
A.FROM
B.WHERE
C.GROUP BY
D.ORDER BY