26 lines
846 B
ReStructuredText
26 lines
846 B
ReStructuredText
Haversine in MySQL
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##################
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:date: 2013-03-05T12:49:28Z
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:category: blog
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:tags: mysql,development
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:url: blog/2013/3/5/haversine-in-mysql.html
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:save_as: blog/2013/3/5/haversine-in-mysql.html
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:status: published
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:author: Gergely Polonkai
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Just insert it in your database, feed them two Google coordinates, and you get the distance in
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kilometres. If you happen to need it in miles, change the constant ``12756.200`` in the
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``RETURN`` row to ``7922.6`` instead.
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.. code-block:: sql
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DELIMITER $$
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CREATE FUNCTION `haversine` (lng1 FLOAT, lat1 FLOAT, lng2 FLOAT, lat2 FLOAT)
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RETURNS float NO SQL DETERMINISTIC
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BEGIN
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SET @a = ABS(POWER(SIN(RADIANS(lat1 - lat2)) / 2, 2) + COS(RADIANS(lat1)) * COS(RADIANS(lat2)) * POWER(SIN(RADIANS(lng1 - lng2)) / 2, 2));
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RETURN 12756.200 * ATAN2(SQRT(@a), SQRT(1 - @a));
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END$$
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