哪条 SELECT 语句可得到单价大于15.00的所有产品的平均单价? ( )
SELECT SUM(*) FROM products WHERE price > 15.00;
SELECT AVG(*) FROM products WHERE price > 15.00;
SELECT AVG(price) FROM products WHERE price > 15.00;
SELECT AVG(DISTINCT price) FROM products GROUP BY price >1 5.00;
