MySQL MIN 查询不适用于计算的距离

Question

我的数据库中有 table 个位置。我需要一个查询来找出最近的位置，提供任何坐标。我编写了以下查询来获取所有行，以及它们与给定坐标的各自距离（以米为单位的距离）：

SELECT *, 111111 * DEGREES(ACOS(LEAST(COS(RADIANS(dest.latitude)) * COS(RADIANS(8.584710)) * COS(RADIANS(dest.longitude - 76.868735)) + SIN(RADIANS(dest.latitude)) * SIN(RADIANS(8.584710)), 1.0))) as  distance FROM offer dest;

它给出以下输出：

+----+------------------------+----------+-----------+------------+---------------------+
| id | description            | latitude | longitude | name       | distance            |
+----+------------------------+----------+-----------+------------+---------------------+
|  2 | Location 1 Description | 8.574858 | 76.874748 | Location 1 |   1278.565430298969 |
| 12 | Location 2 Description | 8.584711 | 76.868738 | Location 2 | 0.35494725284463646 |
+----+------------------------+----------+-----------+------------+---------------------+

一切正常。现在为了获得最小距离，我将 HAVING MIN(distance) 添加到此查询中。现在查询如下所示：

SELECT *, 111111 * DEGREES(ACOS(LEAST(COS(RADIANS(dest.latitude)) * COS(RADIANS(8.584710)) * COS(RADIANS(dest.longitude - 76.868735)) + SIN(RADIANS(dest.latitude)) * SIN(RADIANS(8.584710)), 1.0))) as  distance FROM offer dest having MIN(distance);

现在，此查询应该 return 1 行，并且应该是位置 2，因为它具有最小位置，但这是 returning 位置 1，如下所示：

+----+------------------------+----------+-----------+------------+---------------------+
| id | description            | latitude | longitude | name       | distance            |
+----+------------------------+----------+-----------+------------+---------------------+
|  2 | Location 1 Description | 8.574858 | 76.874748 | Location 1 |   1278.565430298969 |
+----+------------------------+----------+-----------+------------+---------------------+

为什么会这样？我的查询有问题吗？如果是，它是什么以及如何获得最小距离的位置。

Answer 1

HAVING 子句用于过滤组的条件。组在 SELECT 部分和 GROUP BY 中使用聚合函数定义。因为你没有这些，你不应该使用 HAVING.

如果要显示按距离排序的一组行的最小距离并将结果集限制为一行。

SELECT *, 
  111111 * DEGREES(ACOS(LEAST(COS(RADIANS(dest.latitude)) *
  COS(RADIANS(8.584710)) * COS(RADIANS(dest.longitude - 76.868735)) + 
  SIN(RADIANS(dest.latitude)) * SIN(RADIANS(8.584710)), 1.0))) as  distance
FROM offer dest 
ORDER BY distance
LIMIT 1;

MySQL MIN 查询不适用于计算的距离

MySQL MIN query not working for calculated distance

mysql

database

geolocation