1.什么是 Spatial Index？ －－谷歌

2.如何使用
--
-- 表的结构 `wp_address`
--

CREATE TABLE `wp_address` (
  `id` int(11) NOT NULL AUTOINCREMENT,
  `address` char(80) NOT NULL,
  `address_loc` point NOT NULL,
  PRIMARY KEY (`id`),
  SPATIAL KEY `address_loc` (`address_loc`)
) ENGINE=MyISAM DEFAULT CHARSET=utf8;

INSERT INTO `wp_address`  (`address`, `address_loc`) 
 VALUES('Foobar street 01', GeomFromText('POINT(110.3073 50.3821)')),
('Foobar street 02', GeomFromText('POINT(100.3073 60.3821)')),
('Foobar street 03', GeomFromText('POINT(90.3073 70.3821)')),
('Foobar street 04', GeomFromText('POINT(80.3073 80.3821)')),
('Foobar street 05', GeomFromText('POINT(70.3073 90.3821)'));

3.建立Spatial Index 可以在空间数据类型上创建一个spatial index，这个功能只有MyISAM才支持。Index的本质实际上是一个R-TREE，这也是最常用来作为多维数据索引的数据结构。
ALTER TABLE `wp_address` ADD SPATIAL INDEX(address_loc)

4.例，假设需要查找某个矩形区域内所有的点
SELECT *
FROM `wp_address`
WHERE (
X( address_loc ) > 76.3952
)
AND (
X( address_loc ) < 116.4052
)
AND (
Y( address_loc ) > 50.8603
)
AND (
Y( address_loc ) < 90.8703
)
－－检索出来的结果

2	Foobar street 02	[GEOMETRY - 25字节]
	http://www.skyatech.com/phpmyadmin/themes/original/img/b_edit.png	http://www.skyatech.com/phpmyadmin/themes/original/img/b_drop.png	3	Foobar street 03	[GEOMETRY - 25字节]
	http://www.skyatech.com/phpmyadmin/themes/original/img/b_edit.png	http://www.skyatech.com/phpmyadmin/themes/original/img/b_drop.png	4	Foobar street 04	[GEOMETRY - 25字节]

5 计算坐标点之间的距离 坐标 （35.3173，30.3821） 这个太长了没弄明白
SELECT * , ( 2 * 6378.137 * ASIN( SQRT( POW( SIN( PI( ) * ( 111.86141967773438 - 35.3173 ) /360 ) , 2 ) + COS( PI( ) * 33.07078170776367 /180 ) * COS( 35.3173 * PI( ) /180 ) * POW( SIN( PI( ) * ( 33.07078170776367 - 30.3821 ) /360 ) , 2 ) ) ) ) AS juli
FROM `wp_address`
ORDER BY juli
LIMIT 0 , 30
--输出


id address address_loc juli 1 Foobar street 01 [GEOMETRY - 25字节] 8525.788467883413 2 Foobar street 02 [GEOMETRY - 25字节] 8525.788467883413 3 Foobar street 03 [GEOMETRY - 25字节] 8525.788467883413 4 Foobar street 04 [GEOMETRY - 25字节] 8525.788467883413 5 Foobar street 05 [GEOMETRY - 25字节] 8525.788467883413

用 mysql 写存储过程 然后直接调用该函数 计算出距离

DELIMITER //
create procedure Pro_GetDistance( LatBegin REAL , LngBegin REAL , LatEnd REAL , LngEnd REAL )  
BEGIN 
    DECLARE Distance REAL; 
    DECLARE EARTH_RADIUS REAL; 
    DECLARE RadLatBegin REAL;
    DECLARE RadLatEnd REAL;
    DECLARE RadLatDiff REAL;
    DECLARE RadLngDiff REAL;
    SET EARTH_RADIUS = 6378.137;    
    SET RadLatBegin = LatBegin * PI() / 180.0; 
    SET RadLatEnd = LatEnd * PI() / 180.0; 
    SET RadLatDiff = RadLatBegin - RadLatEnd; 
    SET RadLngDiff = LngBegin * PI() / 180.0 - LngEnd * PI() / 180.0; 
     
    SET Distance = 2 * ASIN(SQRT(POWER(Sin(RadLatDiff / 2), 2) + COS(RadLatBegin) * COS(RadLatEnd) * POWER(SIN(RadLngDiff/2),2))); 
    SET Distance = Distance * EARTH_RADIUS ; 
    select Distance;
END;


//调用方法
call Pro_GetDistance(39.94715,116.41085,39.94809,116.4144)
－－output
  Distance 0.32052272149647587

参考 ：http://blog.csdn.net/historyasamirror/article/details/6528527
      http://download.csdn.net/download/xujianfeng2008/4122389
      http://dev.mysql.com/doc/refman/5.1/zh/spatial-extensions-in-mysql.html