Answers:
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;
其中[starlat]和[startlng]是开始测量距离的位置。
创建MySQL表时,您要特别注意lat和lng属性。使用Google地图当前的缩放功能,小数点后只需要6位精度。为了使表所需的存储空间最小,可以指定lat和lng属性为大小为(10,6)的浮点数。这将使字段在小数点后存储6位数字,再在小数点前存储最多4位数字,例如-123.456789度。您的表还应该具有一个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 ;
创建表后,是时候用数据填充它了。以下提供的样本数据是在美国各地散布的约180个披萨饼。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均可导出为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。
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');
要在标记表中查找给定纬度/经度在一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。Wikipedia给出了深入的数学解释,有关该公式与编程的关系的详细讨论位于Movable Type的网站上。
这是一条SQL语句,它将找到距离37,-122坐标25英里范围内的最近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。要按公里而不是英里进行搜索,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;
这是要在小于28英里的距离内查找经度和纬度。
另一个是在28到29英里之间的距离内找到它们:
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 < 29 and distance > 28
ORDER BY distance LIMIT 0, 20;
https://developers.google.com/maps/articles/phpsqlsearch_v3#creating-the-map
HAVING distance < 25
查询25英里半径范围内的位置时进行?
这是我用PHP实现的完整解决方案。
此解决方案使用在http://www.scribd.com/doc/2569355/Geo-Distance-Search-with-MySQL中介绍的Haversine公式。
应该指出的是,Haversine公式在两极都存在弱点。该答案显示了如何实现vincenty大圆距离公式来解决此问题,但是我选择只使用Haversine,因为它足以满足我的目的。
我将纬度存储为DECIMAL(10,8),将经度存储为DECIMAL(11,8)。希望这会有所帮助!
<?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);
?>
<?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;
}
}
?>
<?php
$dbInfo = array(
'host' => "localhost",
'user' => "root",
'pass' => "password"
);
?>
如上面发布的“ Geo-Distance-Search-with-MySQL”一文所建议,可以通过使用MySQL存储过程来提高性能。
我有一个〜17,000个地方的数据库,查询执行时间为0.054秒。
abs
应删除。从度数转换为弧度时,无需获取绝对值,即使您这样做,也只对其中一种纬度进行了测量。请对其进行编辑,以修复该错误。
69
为111,044736
(忘记上面的评论)
以防万一您像我一样懒惰,这是从SO上的其他答案中得到的解决方案。
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;
bounding_distance
代表什么?此值会将结果限制为英里吗?所以在这种情况下,它将在1英里内返回结果?
尝试此操作,它会显示到所提供坐标的最近点(50公里以内)。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
只是改变<table_name>
。<userLat>
和<userLon>
您可以在这里阅读有关此解决方案的更多信息:http : //www.plumislandmedia.net/mysql/haversine-mysql-nearest-loc/
您正在寻找诸如Haversine公式之类的东西。也请参见这里。
还有其他一些,但这是最常引用的。
如果您正在寻找更强大的功能,则可能需要查看数据库的GIS功能。它们能够执行一些很酷的操作,例如告诉您某个点(城市)是否出现在给定的多边形(区域,国家/地区,大陆)内。
根据文章Geo-Distance-Search-with-MySQL检查此代码:
示例:在10英里半径内找到距我当前位置最近的10家酒店:
#Please notice that (lat,lng) values mustn't be negatives to perform all calculations
set @my_lat=34.6087674878572;
set @my_lng=58.3783670308302;
set @dist=10; #10 miles radius
SELECT dest.id, dest.lat, dest.lng, 3956 * 2 * ASIN(SQRT(POWER(SIN((@my_lat -abs(dest.lat)) * pi()/180 / 2),2) + COS(@my_lat * pi()/180 ) * COS(abs(dest.lat) * pi()/180) * POWER(SIN((@my_lng - abs(dest.lng)) * pi()/180 / 2), 2))
) as distance
FROM hotel as dest
having distance < @dist
ORDER BY distance limit 10;
#Also notice that distance are expressed in terms of radius.
该问题的原始答案很好,但是较新版本的mysql(MySQL 5.7.6及更高版本)支持地理查询,因此您现在可以使用内置功能,而不必进行复杂的查询。
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
返回结果,meters
因此,如果您要KM
代替里程使用.0001
而不是里程.000621371192
ST_Distance_Sphere
在主机的install(mysql Ver 15.1 Distrib 10.2.23-MariaDB
)中不存在。我在某个地方读书代替,ST_Distance
但距离遥远。
simpledb.execSQL("CREATE TABLE IF NOT EXISTS " + tablename + "(id INTEGER PRIMARY KEY AUTOINCREMENT,lat double,lng double,address varchar)");
simpledb.execSQL("insert into '" + tablename + "'(lat,lng,address)values('22.2891001','70.780154','craftbox');");
simpledb.execSQL("insert into '" + tablename + "'(lat,lng,address)values('22.2901396','70.7782428','kotecha');");//22.2904718 //70.7783906
simpledb.execSQL("insert into '" + tablename + "'(lat,lng,address)values('22.2863155','70.772108','kkv Hall');");
simpledb.execSQL("insert into '" + tablename + "'(lat,lng,address)values('22.275993','70.778076','nana mava');");
simpledb.execSQL("insert into '" + tablename + "'(lat,lng,address)values('22.2667148','70.7609386','Govani boys hostal');");
double curentlat=22.2667258; //22.2677258
double curentlong=70.76096826;//70.76096826
double curentlat1=curentlat+0.0010000;
double curentlat2=curentlat-0.0010000;
double curentlong1=curentlong+0.0010000;
double curentlong2=curentlong-0.0010000;
try{
Cursor c=simpledb.rawQuery("select * from '"+tablename+"' where (lat BETWEEN '"+curentlat2+"' and '"+curentlat1+"') or (lng BETWEEN '"+curentlong2+"' and '"+curentlong1+"')",null);
Log.d("SQL ", c.toString());
if(c.getCount()>0)
{
while (c.moveToNext())
{
double d=c.getDouble(1);
double d1=c.getDouble(2);
}
}
}
catch (Exception e)
{
e.printStackTrace();
}
查找距我最近的用户:
距离(米)
我有用户表:
+----+-----------------------+---------+--------------+---------------+
| id | email | name | location_lat | location_long |
+----+-----------------------+---------+--------------+---------------+
| 13 | xxxxxx@xxxxxxxxxx.com | Isaac | 17.2675625 | -97.6802361 |
| 14 | xxxx@xxxxxxx.com.mx | Monse | 19.392702 | -99.172596 |
+----+-----------------------+---------+--------------+---------------+
sql:
-- my location: lat 19.391124 -99.165660
SELECT
(ATAN(
SQRT(
POW(COS(RADIANS(users.location_lat)) * SIN(RADIANS(users.location_long) - RADIANS(-99.165660)), 2) +
POW(COS(RADIANS(19.391124)) * SIN(RADIANS(users.location_lat)) -
SIN(RADIANS(19.391124)) * cos(RADIANS(users.location_lat)) * cos(RADIANS(users.location_long) - RADIANS(-99.165660)), 2)
)
,
SIN(RADIANS(19.391124)) *
SIN(RADIANS(users.location_lat)) +
COS(RADIANS(19.391124)) *
COS(RADIANS(users.location_lat)) *
COS(RADIANS(users.location_long) - RADIANS(-99.165660))
) * 6371000) as distance,
users.id
FROM users
ORDER BY distance ASC
地球半径:6371000(以米为单位)
MS SQL Edition在这里:
DECLARE @SLAT AS FLOAT
DECLARE @SLON AS FLOAT
SET @SLAT = 38.150785
SET @SLON = 27.360249
SELECT TOP 10 [LATITUDE], [LONGITUDE], SQRT(
POWER(69.1 * ([LATITUDE] - @SLAT), 2) +
POWER(69.1 * (@SLON - [LONGITUDE]) * COS([LATITUDE] / 57.3), 2)) AS distance
FROM [TABLE] ORDER BY 3
这个问题根本不是很困难,但是如果您需要对其进行优化,它将变得更加复杂。
我的意思是,您的数据库中有100个位置还是1亿个位置?这有很大的不同。
如果位置的数量很少,则只需执行->即可使其脱离SQL并进入代码
Select * from Location
将它们输入代码后,使用Haversine公式计算每个经度/纬度与原始图像之间的距离并将其排序。