假设有两个数据库表,product表和market表,分别存放商品信息和市场需求信息。对SQL语句: select * from product,market where product.p_id=market.p_id的结果描述正确的是( )。如果想从market表中移除m_id为M03的记录,语句( )是正确的。如果要收回GRANT SELECT ON product to role_A WITH GRANT OPTION语句给role_A赋予的权限,使用语句( )。在product表、market表初始数据不变的情况下,以下SQL语句返回的结果有( )条记录。
SELECT product.p_id
FROM product
WHERE product.p_num>( SELECT sum (market.m_need)
FROM market
WHERE market.p_id = product.p_id);
作答
REVOKE SELECT ON product FROM role A
REVOKE SELECT ON product FROM role ACASCADE
REVOKE SELECT ON product FROM role A WITH GRANT OPTION