27 lines
843 B
Markdown
27 lines
843 B
Markdown
|
---
|
||
|
|
layout: post
|
||
|
|
title: "Haversine in MySQL"
|
||
|
|
date: 2013-03-05 12:49:28+00:00
|
||
|
|
permalink: /blog/2013/3/5/haversine-in-mysql
|
||
|
|
tags: [mysql, development]
|
||
|
|
published: true
|
||
|
|
author:
|
||
|
|
name: Gergely Polonkai
|
||
|
|
email: gergely@polonkai.eu
|
||
|
|
---
|
||
|
|
|
||
|
|
Just insert it in your database, feed them two Google coordinates, and you get
|
||
|
|
the distance in kilometres. If you happen to need it in miles, change the
|
||
|
|
constant `12756.200` in the `RETURN` row to `7922.6` instead.
|
||
|
|
|
||
|
|
{% highlight sql %}
|
||
|
|
DELIMITER $$
|
||
|
|
|
||
|
|
CREATE FUNCTION `haversine` (lng1 FLOAT, lat1 FLOAT, lng2 FLOAT, lat2 FLOAT)
|
||
|
|
RETURNS float NO SQL DETERMINISTIC
|
||
|
|
BEGIN
|
||
|
|
SET @a = ABS(POWER(SIN(RADIANS(lat1 - lat2)) / 2, 2) + COS(RADIANS(lat1)) * COS(RADIANS(lat2)) * POWER(SIN(RADIANS(lng1 - lng2)) / 2, 2));
|
||
|
|
RETURN 12756.200 * ATAN2(SQRT(@a), SQRT(1 - @a));
|
||
|
|
END$$
|
||
|
|
{% endhighlight %}
|