Bas*_*sit 163 mysql sql math coordinates computational-geometry
我有纬度和经度,我想从数据库中提取记录,该记录具有最近的纬度和经度,如果该距离长于指定的距离,则不检索它.
表结构:
id
latitude
longitude
place name
city
country
state
zip
sealevel
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Kal*_*tha 191
SELECT latitude, longitude, SQRT(
POW(69.1 * (latitude - [startlat]), 2) +
POW(69.1 * ([startlng] - longitude) * COS(latitude / 57.3), 2)) AS distance
FROM TableName HAVING distance < 25 ORDER BY distance;
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其中[starlat]和[startlng]是开始测量距离的位置.
Igo*_*aka 132
您需要的是将距离转换为经度和纬度,根据大致在边界框中的条目进行过滤,然后进行更精确的距离过滤.这是一篇很好的论文,解释了如何做到这一切:
http://www.scribd.com/doc/2569355/Geo-Distance-Search-with-MySQL
Svi*_*siv 55
创建MySQL表时,需要特别注意lat和lng属性.使用Google地图的当前缩放功能,您应该只需要小数点后的6位精度.要将表所需的存储空间保持在最小,可以指定lat和lng属性是大小为浮点数(10,6).这将使字段在小数点后存储6位数,加上小数点前最多4位数,例如-123.456789度.您的表还应具有id属性作为主键.
CREATE TABLE `markers` (
`id` INT NOT NULL AUTO_INCREMENT PRIMARY KEY ,
`name` VARCHAR( 60 ) NOT NULL ,
`address` VARCHAR( 80 ) NOT NULL ,
`lat` FLOAT( 10, 6 ) NOT NULL ,
`lng` FLOAT( 10, 6 ) NOT NULL
) ENGINE = MYISAM ;
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创建表后,是时候用数据填充它了.下面提供的样本数据是散布在美国各地的大约180个pizzarias.在phpMyAdmin中,您可以使用IMPORT选项卡导入各种文件格式,包括CSV(逗号分隔值).Microsoft Excel和Google Spreadsheets都导出为CSV格式,因此您可以通过导出/导入CSV文件轻松地将数据从电子表格传输到MySQL表格.
INSERT INTO `markers` (`name`, `address`, `lat`, `lng`) VALUES ('Frankie Johnnie & Luigo Too','939 W El Camino Real, Mountain View, CA','37.386339','-122.085823');
INSERT INTO `markers` (`name`, `address`, `lat`, `lng`) VALUES ('Amici\'s East Coast Pizzeria','790 Castro St, Mountain View, CA','37.38714','-122.083235');
INSERT INTO `markers` (`name`, `address`, `lat`, `lng`) VALUES ('Kapp\'s Pizza Bar & Grill','191 Castro St, Mountain View, CA','37.393885','-122.078916');
INSERT INTO `markers` (`name`, `address`, `lat`, `lng`) VALUES ('Round Table Pizza: Mountain View','570 N Shoreline Blvd, Mountain View, CA','37.402653','-122.079354');
INSERT INTO `markers` (`name`, `address`, `lat`, `lng`) VALUES ('Tony & Alba\'s Pizza & Pasta','619 Escuela Ave, Mountain View, CA','37.394011','-122.095528');
INSERT INTO `markers` (`name`, `address`, `lat`, `lng`) VALUES ('Oregano\'s Wood-Fired Pizza','4546 El Camino Real, Los Altos, CA','37.401724','-122.114646');
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要在标记表中查找位于给定纬度/经度的特定半径范围内的位置,可以使用基于Haversine公式的SELECT语句.Haversine公式通常用于计算球体上两对坐标之间的大圆距离.维基百科给出了一个深入的数学解释,并且关于编程的一个很好的讨论是在Movable Type的网站上进行的.
这是SQL语句,它将找到距离37,-122坐标25英里半径范围内最近的20个位置.它根据该行的纬度/经度和目标纬度/经度计算距离,然后仅询问距离值小于25的行,按距离对整个查询进行排序,并将其限制为20个结果.要以公里而不是里程搜索,请将3959替换为6371.
SELECT
id,
(
3959 *
acos(cos(radians(37)) *
cos(radians(lat)) *
cos(radians(lng) -
radians(-122)) +
sin(radians(37)) *
sin(radians(lat )))
) AS distance
FROM markers
HAVING distance < 28
ORDER BY distance LIMIT 0, 20;
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https://developers.google.com/maps/articles/phpsqlsearch_v3#creating-the-map
cir*_*try 28
这是我在PHP中实现的完整解决方案.
此解决方案使用http://www.scribd.com/doc/2569355/Geo-Distance-Search-with-MySQL中提供的Haversine公式.
值得注意的是,Haversine公式在极点周围存在弱点.这个答案显示了如何实现vincenty Great Circle Distance公式来解决这个问题,但是我选择使用Haversine,因为它对我的目的来说已经足够了.
我将纬度存储为DECIMAL(10,8),经度存储为DECIMAL(11,8).希望这有帮助!
<?PHP
/**
* Use the Haversine Formula to display the 100 closest matches to $origLat, $origLon
* Only search the MySQL table $tableName for matches within a 10 mile ($dist) radius.
*/
include("./assets/db/db.php"); // Include database connection function
$db = new database(); // Initiate a new MySQL connection
$tableName = "db.table";
$origLat = 42.1365;
$origLon = -71.7559;
$dist = 10; // This is the maximum distance (in miles) away from $origLat, $origLon in which to search
$query = "SELECT name, latitude, longitude, 3956 * 2 *
ASIN(SQRT( POWER(SIN(($origLat - latitude)*pi()/180/2),2)
+COS($origLat*pi()/180 )*COS(latitude*pi()/180)
*POWER(SIN(($origLon-longitude)*pi()/180/2),2)))
as distance FROM $tableName WHERE
longitude between ($origLon-$dist/cos(radians($origLat))*69)
and ($origLon+$dist/cos(radians($origLat))*69)
and latitude between ($origLat-($dist/69))
and ($origLat+($dist/69))
having distance < $dist ORDER BY distance limit 100";
$result = mysql_query($query) or die(mysql_error());
while($row = mysql_fetch_assoc($result)) {
echo $row['name']." > ".$row['distance']."<BR>";
}
mysql_close($db);
?>
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<?PHP
/**
* Class to initiate a new MySQL connection based on $dbInfo settings found in dbSettings.php
*
* @example $db = new database(); // Initiate a new database connection
* @example mysql_close($db); // close the connection
*/
class database{
protected $databaseLink;
function __construct(){
include "dbSettings.php";
$this->database = $dbInfo['host'];
$this->mysql_user = $dbInfo['user'];
$this->mysql_pass = $dbInfo['pass'];
$this->openConnection();
return $this->get_link();
}
function openConnection(){
$this->databaseLink = mysql_connect($this->database, $this->mysql_user, $this->mysql_pass);
}
function get_link(){
return $this->databaseLink;
}
}
?>
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<?php
$dbInfo = array(
'host' => "localhost",
'user' => "root",
'pass' => "password"
);
?>
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通过使用上面发布的"Geo-Distance-Search-with-MySQL"文章所建议的MySQL存储过程,可以提高性能.
我有一个~17,000个地方的数据库,查询执行时间是0.054秒.
Eva*_*van 24
如果你像我一样懒惰,这里有一个解决方案,从这个和其他答案合并到SO.
set @orig_lat=37.46;
set @orig_long=-122.25;
set @bounding_distance=1;
SELECT
*
,((ACOS(SIN(@orig_lat * PI() / 180) * SIN(`lat` * PI() / 180) + COS(@orig_lat * PI() / 180) * COS(`lat` * PI() / 180) * COS((@orig_long - `long`) * PI() / 180)) * 180 / PI()) * 60 * 1.1515) AS `distance`
FROM `cities`
WHERE
(
`lat` BETWEEN (@orig_lat - @bounding_distance) AND (@orig_lat + @bounding_distance)
AND `long` BETWEEN (@orig_long - @bounding_distance) AND (@orig_long + @bounding_distance)
)
ORDER BY `distance` ASC
limit 25;
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She*_*man 15
该问题的原始答案很好,但较新版本的 mysql(MySQL 5.7.6 上)支持地理查询,因此您现在可以使用内置功能而不是进行复杂的查询。
您现在可以执行以下操作:
select *, ST_Distance_Sphere( point ('input_longitude', 'input_latitude'),
point(longitude, latitude)) * .000621371192
as `distance_in_miles`
from `TableName`
having `distance_in_miles` <= 'input_max_distance'
order by `distance_in_miles` asc
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结果在 中返回meters。所以如果你想KM简单地使用.001而不是.000621371192(这是英里)。
小智 12
容易一个;)
SELECT * FROM `WAYPOINTS` W ORDER BY
ABS(ABS(W.`LATITUDE`-53.63) +
ABS(W.`LONGITUDE`-9.9)) ASC LIMIT 30;
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只需用您需要的坐标替换坐标.值必须存储为double.这是一个有效的MySQL 5.x示例.
干杯
试试这个,它会显示距离提供的坐标最近的点(50 公里内)。它完美地工作:
SELECT m.name,
m.lat, m.lon,
p.distance_unit
* DEGREES(ACOS(COS(RADIANS(p.latpoint))
* COS(RADIANS(m.lat))
* COS(RADIANS(p.longpoint) - RADIANS(m.lon))
+ SIN(RADIANS(p.latpoint))
* SIN(RADIANS(m.lat)))) AS distance_in_km
FROM <table_name> AS m
JOIN (
SELECT <userLat> AS latpoint, <userLon> AS longpoint,
50.0 AS radius, 111.045 AS distance_unit
) AS p ON 1=1
WHERE m.lat
BETWEEN p.latpoint - (p.radius / p.distance_unit)
AND p.latpoint + (p.radius / p.distance_unit)
AND m.lon BETWEEN p.longpoint - (p.radius / (p.distance_unit * COS(RADIANS(p.latpoint))))
AND p.longpoint + (p.radius / (p.distance_unit * COS(RADIANS(p.latpoint))))
ORDER BY distance_in_km
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只是改变<table_name>。<userLat>和<userLon>
您可以在此处阅读有关此解决方案的更多信息:http : //www.plumislandmedia.net/mysql/haversine-mysql-nearest-loc/