如何通过聚合列过滤非聚合查询结果？

Question

我正在创建价格比较服务。一个 Site 的产品与一个或多个 Sites 的产品进行比较。使用 ProductMatch table:

将产品从一个 Site 匹配到另一个

给定以下查询以提取产品及其匹配项：

SELECT
    p1.id AS p1_id, p1.name AS p1_name, p1.price AS p1_price,
    p2.id AS p2_id, p2.name AS p2_name, p2.price AS p2_price,
    m.time
FROM Product p1
LEFT JOIN ProductMatch m ON m.fromProduct_id = p1.id
LEFT JOIN Product p2 ON m.toProduct_id = p2.id

WHERE p1.site_id = 1;

如何筛选价格 (p1.price) 低于最低竞争对手价格 (MIN(p2.price)) 的产品？

使用子查询，我会这样做：

SELECT
    p1.id AS p1_id, p1.name AS p1_name, p1.price AS p1_price,
    p2.id AS p2_id, p2.name AS p2_name, p2.price AS p2_price,
    m.time
FROM Product p1
LEFT JOIN ProductMatch m ON m.fromProduct_id = p1.id
LEFT JOIN Product p2 ON m.toProduct_id = p2.id

WHERE p1.id IN (
    SELECT x.id FROM (
        SELECT _p1.id, _p1.price
        FROM Product _p1
        JOIN ProductMatch _m ON _m.fromProduct_id = _p1.id
        JOIN Product _p2 ON _m.toProduct_id = _p2.id
        WHERE _p1.site_id = 1
        GROUP BY _p1.id
        HAVING _p1.price < MIN(_p2.price)
    ) x
);

是否可以简化此查询以不使用子查询？

我的顾虑：

在子查询中重复完全相同的连接感觉很奇怪
我担心子查询在较大数据集上的性能
子查询在我的 ORM 中表现不佳

Answer 1

在 CTE 中使用 MIN() window 函数将被过滤：

WITH cte AS (
  SELECT
    p1.id AS p1_id, p1.name AS p1_name, p1.price AS p1_price,
    p2.id AS p2_id, p2.name AS p2_name, p2.price AS p2_price,
    m.time,
    MIN(p2.price) OVER (PARTITION BY p1.id) AS min_price
  FROM Product p1
  LEFT JOIN ProductMatch m ON m.fromProduct_id = p1.id
  LEFT JOIN Product p2 ON m.toProduct_id = p2.id
  WHERE p1.site_id = 1
)
SELECT 
  p1_id, p1_name, p1_price,
  p2_id, p2_name, p2_price,
  time
FROM cte
WHERE p1_price < min_price

如何通过聚合列过滤非聚合查询结果？

How to filter nonaggregated query results by an aggregated column?

mysql

sql

mysql-8.0