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问题:
I have latitude and longitude and I want to pull the record from the database, which has nearest latitude and longitude by the distance, if that distance gets longer than specified one, then don\'t retrieve it.
Table structure:
id
latitude
longitude
place name
city
country
state
zip
sealevel
回答1:
What you need is to translate the distance into degrees of longitude and latitude, filter based on those to bound the entries that are roughly in the bounding box, then do a more precise distance filter. Here is great paper that explains how to do all this:
http://www.scribd.com/doc/2569355/Geo-Distance-Search-with-MySQL
回答2:
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;
where [starlat] and [startlng] is the position where to start measuring the distance.
回答3:
Google\'s solution:
Creating the Table
When you create the MySQL table, you want to pay particular attention to the lat and lng attributes. With the current zoom capabilities of Google Maps, you should only need 6 digits of precision after the decimal. To keep the storage space required for your table at a minimum, you can specify that the lat and lng attributes are floats of size (10,6). That will let the fields store 6 digits after the decimal, plus up to 4 digits before the decimal, e.g. -123.456789 degrees. Your table should also have an id attribute to serve as the primary key.
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 ;
Populating the Table
After creating the table, it\'s time to populate it with data. The sample data provided below is for about 180 pizzarias scattered across the United States. In phpMyAdmin, you can use the IMPORT tab to import various file formats, including CSV (comma-separated values). Microsoft Excel and Google Spreadsheets both export to CSV format, so you can easily transfer data from spreadsheets to MySQL tables through exporting/importing CSV files.
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\');
Finding Locations with MySQL
To find locations in your markers table that are within a certain radius distance of a given latitude/longitude, you can use a SELECT statement based on the Haversine formula. The Haversine formula is used generally for computing great-circle distances between two pairs of coordinates on a sphere. An in-depth mathemetical explanation is given by Wikipedia and a good discussion of the formula as it relates to programming is on Movable Type\'s site.
Here\'s the SQL statement that will find the closest 20 locations that are within a radius of 25 miles to the 37, -122 coordinate. It calculates the distance based on the latitude/longitude of that row and the target latitude/longitude, and then asks for only rows where the distance value is less than 25, orders the whole query by distance, and limits it to 20 results. To search by kilometers instead of miles, replace 3959 with 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 < 25
ORDER BY distance LIMIT 0, 20;
https://developers.google.com/maps/articles/phpsqlsearch_v3#creating-the-map
回答4:
Here is my full solution implemented in PHP.
This solution uses the Haversine formula as presented in http://www.scribd.com/doc/2569355/Geo-Distance-Search-with-MySQL.
It should be noted that the Haversine formula experiences weaknesses around the poles. This answer shows how to implement the vincenty Great Circle Distance formula to get around this, however I chose to just use Haversine because it\'s good enough for my purposes.
I\'m storing latitude as DECIMAL(10,8) and longitude as DECIMAL(11,8). Hopefully this helps!
showClosest.php
<?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);
?>
./assets/db/db.php
<?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;
}
}
?>
./assets/db/dbSettings.php
<?php
$dbInfo = array(
\'host\' => \"localhost\",
\'user\' => \"root\",
\'pass\' => \"password\"
);
?>
It may be possible to increase performance by using a MySQL stored procedure as suggested by the \"Geo-Distance-Search-with-MySQL\" article posted above.
I have a database of ~17,000 places and the query execution time is 0.054 seconds.
回答5:
Just in case you are lazy like me, here\'s a solution amalgamated from this and other answers on 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;
回答6:
Easy one ;)
SELECT * FROM `WAYPOINTS` W ORDER BY
ABS(ABS(W.`LATITUDE`-53.63) +
ABS(W.`LONGITUDE`-9.9)) ASC LIMIT 30;
Just replace the coordinates with your required ones. The values have to be stored as double. This ist a working MySQL 5.x example.
Cheers
回答7:
You\'re looking for things like the haversine formula. See here as well.
There\'s other ones but this is the most commonly cited.
If you\'re looking for something even more robust, you might want to look at your databases GIS capabilities. They\'re capable of some cool things like telling you whether a point (City) appears within a given polygon (Region, Country, Continent).
回答8:
Check this code based on the article Geo-Distance-Search-with-MySQL:
Example: find the 10 nearest hotels to my current location in a 10 miles radius:
#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.
回答9:
Try this, it show the nearest points to provided coordinates (within 50 km). It works perfectly:
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
Just change <table_name>
. <userLat>
and <userLon>
You can read more about this solution here: http://www.plumislandmedia.net/mysql/haversine-mysql-nearest-loc/
回答10:
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();
}
回答11:
It sounds like you want to do a nearest neighbour search with some bound on the distance. SQL does not support anything like this as far as I am aware and you would need to use an alternative data structure such as an R-tree or kd-tree.
回答12:
Find nearest Users to my:
Distance in meters
Based in Vincenty\'s formula
i have User table:
+----+-----------------------+---------+--------------+---------------+
| 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
radius of the earth : 6371000 ( in meters)
回答13:
Sounds like you should just use PostGIS, SpatialLite, SQLServer2008, or Oracle Spatial. They can all answer this question for you with spatial SQL.
回答14:
You should try these:
http://en.wikipedia.org/wiki/Great-circle_distance
http://code.google.com/apis/maps/articles/phpsqlsearch.html
回答15:
In extreme cases this approach fails, but for performance, I\'ve skipped the trigonometry and simply calculated the diagonal squared.
回答16:
MS SQL Edition here:
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
回答17:
The original answers to the question are good, but newer versions of mysql (MySQL 5.7.6 on) support geo queries, so you can now use built in functionality rather than doing complex queries.
You can now do something like:
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
The results are returned in meters
so if you want KM
instead of miles use .0001
instead of .000621371192
MySql docs are here
回答18:
This problem is not very hard at all, but it gets more complicated if you need to optimize it.
What I mean is, do you have 100 locations in your database or 100 million? It makes a big difference.
If the number of locations is small, get them out of SQL and into code by just doing ->
Select * from Location
Once you get them into code, calculate the distance between each lat/lon and your original with the Haversine formula and sort it.