您检查COUNT(DISTINCT price > 1)的想法是正确的。
我们只需要在HAVING子句中使用GROUP BY：

SELECT product_id
FROM t1
GROUP BY product_id
HAVING COUNT (DISTINCT price) > 1
ORDER BY product_id;

如果还应显示不同的价格，则此查询可用作子查询。例如：

SELECT product_id, price
FROM t1
WHERE product_id IN 
(SELECT product_id
FROM t1
GROUP BY product_id
HAVING COUNT (DISTINCT price) > 1)
ORDER BY product_id;

或者我们可以使用JOIN而不是IN，后者的性能更好：

SELECT t1.product_id, t1.price
FROM t1
JOIN  
(SELECT product_id
FROM t1
GROUP BY product_id
HAVING COUNT (DISTINCT price) > 1) sub
ON t1.product_id = sub.product_id
ORDER BY t1.product_id;

我们可以在这里尝试这些查询：db<>fiddle