使用点表查找最近的点

I have a DB Schema like this (from this tutorial by Google) -

我有一个这样的DB模式(来自本教程的谷歌)-

So the actual points in a graph for them is like this-

图中的实际点是这样的。

What I want is to find points near a given point (by point_id) point ordered by distance

我想要的是找到一个给定点(由point_id)附近的点(由距离排序)

Location of a point (x,y) is (point_x,point_y) in DB

点(x,y)的位置在DB中为(point_x,point_y)

I want to solve it with MySQL because my DB is already in MySQL.

我想用MySQL解决因为我的DB已经在MySQL中了。

---

Update-

Finding distance of 2 points is so easy like this-

求两点的距离就像这样简单

I want to sort on distance with MySQL.

我想用MySQL进行距离排序。

---

Re-

For removing the confusions, I want the points inside the circle, later. But now I want to find only the sorted points.

为了消除混淆，我希望在后面的圆中有点。但现在我只想找到排序后的点。

So u can ignore the circles.

所以u可以忽略这些圆。

---

I don't have any idea how to do it, can anyone please help?

我不知道怎么做，谁能帮忙吗?

2 个解决方案

#1

I have found a better solution than @1000111 's solution.

我找到了一个比@1000111的更好的解决方案。

There is custom DB type in MySQL for this kind of data which gives a better performance.

MySQL中有针对这种数据的自定义DB类型，可以提供更好的性能。

OpenGIS in MySQL is perfect for this.

MySQL中的OpenGIS非常适合这种情况。

Functions are given here.

函数给出。

An illustrative definition is given in this * question.

这个*问题给出了一个说明性的定义。

My solution is like this-

我的解决办法是这样的。

DB Table-

数据库表,

CREATE TABLE geoTable
(
    id INT(6) UNSIGNED AUTO_INCREMENT PRIMARY KEY,
    name VARCHAR(30) NOT NULL,
    geoPoint POINT NOT NULL,
    SPATIAL INDEX(geoPoint)
) ENGINE=MyISAM;


INSERT INTO geoTable (name, geoPoint)
VALUES
  ( "A", GeomFromText('POINT(0.1 -1.01)') ),
  ( "B", ST_GeomFromText('POINT(56.31 2.81)') ),
  ( "C", ST_GeomFromText('POINT(11.1 1.176)') ),
  ( "ui", ST_GeomFromText('POINT(9.1 2.1)') );

SQL Query-

SQL查询,

SELECT
  id,
  name,
  X(geoPoint) AS "latitude",
  Y(geoPoint) AS "longitude",
  (
    GLength(
      LineStringFromWKB(
        LineString(
          geoPoint, 
          GeomFromText('POINT(51.5177 -0.0968)')
        )
      )
    )
  )
  AS distance
FROM geoTable
  ORDER BY distance ASC;

---

An example SQL Fiddle is given here.

See the execution time-

看到了执行时间

For 150 entry, it is only 13ms.

在150个词条中，只有13ms。

#2

Try this query please [a straight forward approach]:

请尝试这个查询[一个直接的方法]:

Suppose, you want to find the nearest 20 points of the point having point_id = 5

假设您希望找到具有point_id = 5的点的最近20个点

SET @givent_point_id := 5;

设置@givent_point_id:= 5;

SELECT 
P1.point_id,
P1.point_name,
P1.point_x,
P1.point_y,
(POW(ABS((P2.point_x - P1.point_x)),2) + POW(ABS((P2.point_y - P1.point_y)),2)) AS sqr_distance
FROM Point P1,
    (SELECT point_x,point_y FROM Point WHERE point_id = @givent_point_id) P2
WHERE P1.point_id <> @givent_point_id
ORDER BY sqr_distance
LIMIT 20;

Demo Here

演示

More: You may have a look at MySQL SPATIAL DATATYPE.

更多信息:您可以查看MySQL空间数据类型。

MySQL spatial indexes use R-tree as data structure which is specially designed for spatial access methods.

MySQL空间索引使用R-tree作为数据结构，是专门为空间访问方法设计的。

R-trees are tree data structures used for spatial access methods, i.e., for indexing multi-dimensional information such as geographical coordinates, rectangles or polygons.

r树是用于空间访问方法的树数据结构，即。，用于索引地理坐标、矩形或多边形等多维信息。