MySQL - 在空间点附近选择 [英] MySQL - selecting near a spatial point

问题描述

我根据下面的查询来选择另一个 SO 解决方案，但在过去的几个小时里，我无法让它返回任何结果，我现在有点急躁...... p>

我的表 lastcrawl 有一个简单的模式:

<上一页>id(主要 int，autoinc)点(空间点)

(通过ALTER TABLE lastcrawl ADD SPATIAL INDEX(point);添加空间键；)

<上一页>$query = sprintf("SELECT * FROM lastcrawl WHEREMBRContains(LineFromText(CONCAT('(', %F + 0.0005 * ( 111.1/cos(%F)), ' ', %F + 0.0005/111.1, ',', %F - 0.0005/( 111.1/cos(%F)), ' ', %F - 0.0005/111.1, ')' )，观点)"，$lng,$lng,$lat,$lng,$lat,$lat);$result = mysql_query($query) 或死 (mysql_error());

我已经通过以下方式成功插入了几行:

$query = sprintf("INSERT INTO lastcrawl (point) VALUES(GeomFromText('POINT(%F %F)'))",$lat,$lng);

但是，我无法查询最近的点来获得非空结果集.如何让查询选择离给定空间点最近的点?

<小时>

插入 $lat=40, $lng=-100 后，尝试查询它也不会返回任何内容(因此，甚至不匹配精确坐标):

SELECT * FROM lastcrawl WHERE MBRContains(LineFromText(CONCAT( '(' , -100.000000 + 0.0005 * ( 111.1/cos(-100.000000)) , ' ' , 40.000000 + 0.0005/111.1 , ',' , -100.000000 - 0.0005/( 111.1/cos(40.000000)) , ' ' , 40.000000 - 0.0005/111.1 , ')' )) ,point)

解决方案

我稍微修正了公式.

这个对我有用:

CREATE TABLE lastcrawl (id INT NOT NULL PRIMARY KEY, pnt POINT NOT NULL) ENGINE=MyISAM;插入进入最后一次爬行值(1，点(40，-100))；设置@lat = 40；设置@lon = -100；选择  *来自最后一次爬行WHERE MBR包含(线串(观点(@lat + 10/111.1,@lon + 10/( 111.1/COS(RADIANS(@lat)))),观点    (@lat - 10/111.1，@lon - 10/( 111.1/COS(RADIANS(@lat))))),点);

I've based my query below to select points near a spatial point called point on the other SO solution, but I've not been able to get it to return any results, for the past few hours, and I'm a bit edgy now...

My table lastcrawl has a simple schema:

 id (primary int, autoinc)
 point (spatial POINT)

(Added the spatial key via ALTER TABLE lastcrawl ADD SPATIAL INDEX(point);)

$query = sprintf("SELECT * FROM lastcrawl WHERE  
     MBRContains(LineFromText(CONCAT(
        '('
        , %F + 0.0005 * ( 111.1 / cos(%F))
        , ' '
        , %F + 0.0005 / 111.1
        , ','
        , %F - 0.0005 / ( 111.1 / cos(%F))
        , ' '
        , %F - 0.0005 / 111.1 
        , ')' )
        ,point)",
        $lng,$lng,$lat,$lng,$lat,$lat);
$result = mysql_query($query) or die (mysql_error()); 

I've successfully inserted a few rows via:

$query = sprintf("INSERT INTO lastcrawl (point) VALUES( GeomFromText( 'POINT(%F %F)' ))",$lat,$lng);

But, I'm just not able to query the nearest points to get a non-null result set. How do you get the query to select the points nearest to a given spatial point?

---

After inserting $lat=40, $lng=-100, trying to query this returns nothing as well (so, not even exact coordinates match):

SELECT * FROM lastcrawl WHERE MBRContains(LineFromText(CONCAT( '(' , -100.000000 + 0.0005 * ( 111.1 / cos(-100.000000)) , ' ' , 40.000000 + 0.0005 / 111.1 , ',' , -100.000000 - 0.0005 / ( 111.1 / cos(40.000000)) , ' ' , 40.000000 - 0.0005 / 111.1 , ')' )) ,point)

解决方案

I've corrected the formula a little.

This one works for me:

CREATE TABLE lastcrawl (id INT NOT NULL PRIMARY KEY, pnt POINT NOT NULL) ENGINE=MyISAM;

INSERT
INTO    lastcrawl
VALUES  (1, POINT(40, -100));

SET @lat = 40;
SET @lon = -100;

SELECT  *
FROM    lastcrawl
WHERE   MBRContains
                (
                LineString
                        (
                        Point
                                 (
                                 @lat + 10 / 111.1,
                                 @lon + 10 / ( 111.1 / COS(RADIANS(@lat)))
                                 ),
                        Point    (
                                 @lat - 10 / 111.1,
                                 @lon - 10 / ( 111.1 / COS(RADIANS(@lat)))
                                 )
                        ),
                pnt
                );

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