mysql中geometry类型的简单使用
创建表格脚本
CREATE TABLE `z_gis` (
`id` varchar(45) NOT NULL,
`name` varchar(10) NOT NULL COMMENT '姓名',
`gis` geometry NOT NULL COMMENT '空间位置信息',
`geohash` varchar(20) GENERATED ALWAYS AS (st_geohash(`gis`,8)) VIRTUAL,
PRIMARY KEY (`id`),
UNIQUE KEY `id` (`id`),
SPATIAL KEY `idx_gis` (`gis`),
KEY `idx_geohash` (`geohash`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COMMENT='空间位置信息'
这里我创建了一张位置信息表,每个人对应的经纬度都会以geometry类型存在表中,geohash字段是把坐标系分成很多小方格,然后将经纬度转化成字符串,其原理可自行百度,在这里就不多说了。
哦,对了,geometry类型好像不能为null,所以建表时必须为not null。
插入表数据
insert into z_gis(id,name,gis) values
(replace(uuid(),'-',''),'张三',geomfromtext('point(108.9498710632 34.2588125935)')),
(replace(uuid(),'-',''),'李四',geomfromtext('point(108.9465236664 34.2598766768)')),
(replace(uuid(),'-',''),'王五',geomfromtext('point(108.9477252960 34.2590342786)')),
(replace(uuid(),'-',''),'赵六',geomfromtext('point(108.9437770844 34.2553719653)')),
(replace(uuid(),'-',''),'小七',geomfromtext('point(108.9443349838 34.2595663206)')),
(replace(uuid(),'-',''),'孙八',geomfromtext('point(108.9473497868 34.2643456798)')),
(replace(uuid(),'-',''),'十九',geomfromtext('point(108.9530360699 34.2599476152)'));
geomfromtext()函数是将字符串格式的点坐标,转化成geometry类型,还有个字段geohash是根据gis字段的值自动生成的,可以仔细看看建表脚本。
查询
1. 查询张三的经纬度信息
select name, astext(gis) gis from z_gis where name = '张三';
astext()函数是将geometry类型转化为字符串
2. 修改张三的位置信息
update z_gis set gis = geomfromtext('point(108.9465236664 34.2598766768)') where name = '张三';
3. 查询张三和李四之间的距离
select floor(st_distance_sphere(
(select gis from z_gis where name= '张三'),
gis
)) distance from z_gis where name= '李四';
sql执行结果
4. 查询距离张三500米内的所有人
SELECT
name,
FLOOR(ST_DISTANCE_SPHERE((SELECT
gis
FROM
z_gis
WHERE
name = '张三'),
gis)) distance,
astext(gis) point
FROM
z_gis
WHERE
ST_DISTANCE_SPHERE((SELECT
gis
FROM
z_gis
WHERE
name = '张三'),
gis) < 500
AND name != '张三';
sql执行结果
name distance point
李四 329 POINT(108.9465236664 34.2598766768)
王五 198 POINT(108.947725296 34.2590342786)
十九 317 POINT(108.9530360699 34.2599476152)
如果表中数据非常多时,这样查效率会非常低,这时就会用到geohash字段查询
SELECT
name,
floor(ST_DISTANCE_SPHERE((SELECT
gis
FROM
z_gis
WHERE
name = '张三'),
gis)) distance,
astext(gis) point
FROM
z_gis
WHERE
geohash like concat(left((select geohash from z_gis where name = '张三'),6),'%')
AND ST_DISTANCE_SPHERE((SELECT
gis
FROM
z_gis
WHERE
name = '张三'),
gis) < 500
AND name != '张三';