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  • mysql中 地里位置搜索 (抄)

    mysql中geometry类型的简单使用

    ozil_oo
    0.1892018.08.09 10:31:48字数 304阅读 4,012

    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';  
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  • 原文地址:https://www.cnblogs.com/xiangzideheiniu/p/11772761.html
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