MySQL - 按最小差异搜索日期范围和分组

如何解决MySQL - 按最小差异搜索日期范围和分组

我需要找到尽可能接近人们搜索的所需日期范围的所有物品的一个价格。一个对象可以有不同日期范围的多个价格。

价格表

id	objectid	价格	开始	结束
1	21	50	2021-01-01	2021-04-01
2	21	60	2021-04-02	2021-08-01
3	22	30	2021-01-01	2021-04-01
4	23	150	2021-01-01	2021-04-01
5	21	20	2021-08-02	2021-09-01
6	23	120	2021-07-01	2021-08-01

假设人们在 2021-05-01 和 2021-06-01 之间搜索，结果应该是：

id	objectid	价格
2	21	60
3	22	30
6	23	120

我正在处理这个查询，但在某处我失去了注意力。

SELECT p.objectid,p.id
    p.start,p.end,p.price,ABS(DATEDIFF(p.start,'2021-05-01') + DATEDIFF(p.end,'2021-06-01')) diff
FROM
    prices AS p1
INNER JOIN(
    SELECT
        p.objectid,MIN(
            ABS(
                DATEDIFF(start,'2021-05-01') + DATEDIFF(end,'2021-06-01')
            )
        ) AS diff
    FROM
        prices p
    GROUP BY
        p.objectid
) p2
ON
    p1.objectid = p2.objectid AND diff = p2.diff

解决方法

您可以通过自加入来实现这一点。
试试这个下面的查询

SELECT
    Y.id,Y.objectid,Y.price
FROM
    (
    SELECT
        *,ABS(
            DATEDIFF(`start`,'2021-05-01') + DATEDIFF(`end`,'2021-06-01')
        ) AS `diff`
    FROM
        price
) AS Y
INNER JOIN(
    SELECT
        *,MIN(
            ABS(
                DATEDIFF(`start`,'2021-06-01')
            )
        ) AS diff
    FROM
        price
    GROUP BY
        objectid
) AS X
ON
    X.objectid = Y.objectid AND X.diff = Y.diff
ORDER BY
    Y.id

o/p 是这个

这是一个接缝工作的解决方案，但我猜对差异进行连接可能会导致结果模糊。

SELECT p.objectid,p.id
    p.start,p.end,p.price
FROM
    prices AS p1
INNER JOIN(
    SELECT
        p.objectid,MIN(
            ABS(
                DATEDIFF(start,'2021-05-01') + DATEDIFF(end,'2021-06-01')
            )
        ) AS diff
    FROM
        prices p
    GROUP BY
        p.objectid
) p2
ON
    p1.objectid = p2.objectid AND (ABS(DATEDIFF(p.start,'2021-05-01') + DATEDIFF(p.end,'2021-06-01'))) = p2.diff