Joins on spatial mysql indexes

Question

I have two tables: one with points, the other with polys.

CREATE TABLE `points` (
  `id` int(10) unsigned NOT NULL AUTO_INCREMENT,
  `point` point NOT NULL,
  PR         


        

Answer 1

You can force MySQL to use the index by encapsulating the subselect in a function.

For example:

DELIMITER $$

DROP FUNCTION IF EXISTS `GetMyPolygon`$$
CREATE DEFINER=`root`@`localhost` FUNCTION `GetMyPolygon`(p POINT) RETURNS INTEGER
BEGIN

DECLARE ret INTEGER;

SET ret = (SELECT range_id FROM ranges WHERE ST_CONTAINS(poly, p) ;

RETURN ret;

END$$

If polygons do not overlap, you can then make:

SELECT *, GetMyPolygon(point) FROM points 

If they do overlap, but there a few, you could make a similar function that makes group_concat...