3 用SQL块编程完成下列查询要求： （1）求购买了供应商"宝洁"产品的所有顾客； （2）求购买的商品包含了顾客"Dennis"所购买的所有商品的顾客（姓名）； （3）求牙膏卖出数量最多的供应商。 （4）将所有的牙膏商品单价增加10%。(SQL语句) （5） 删除从未被购买的商品记录。(SQL语句)

1. 求购买了供应商"宝洁"产品的所有顾客：

SELECT DISTINCT c.name FROM customer c, orders o, order_details od, product p, supplier s 
WHERE c.customer_id = o.customer_id 
AND o.order_id = od.order_id 
AND od.product_id = p.product_id 
AND p.supplier_id = s.supplier_id 
AND s.supplier_name = '宝洁';

2. 求购买的商品包含了顾客"Dennis"所购买的所有商品的顾客（姓名）：

SELECT DISTINCT c.name FROM customer c, orders o, order_details od, product p 
WHERE c.customer_id = o.customer_id 
AND o.order_id = od.order_id 
AND od.product_id = p.product_id 
AND p.product_name IN (
    SELECT DISTINCT p.product_name FROM customer c, orders o, order_details od, product p 
    WHERE c.name = 'Dennis' 
    AND c.customer_id = o.customer_id 
    AND o.order_id = od.order_id 
    AND od.product_id = p.product_id
);

3. 求牙膏卖出数量最多的供应商：

SELECT s.supplier_name FROM supplier s, product p, order_details od 
WHERE s.supplier_id = p.supplier_id 
AND p.product_id = od.product_id 
AND p.product_name = '牙膏' 
GROUP BY s.supplier_name 
ORDER BY SUM(od.quantity) DESC 
LIMIT 1;

4. 将所有的牙膏商品单价增加10%：

UPDATE product SET price = price * 1.1 WHERE product_name = '牙膏';

5. 删除从未被购买的商品记录：

DELETE FROM product WHERE product_id NOT IN (SELECT product_id FROM order_details);