mysql根据经纬度获取附近的商家

create table geo(
    geo_id INT NOT NULL AUTO_INCREMENT,
    lng float NOT NULL,
    lat float NOT NULL,
    name VARCHAR(100) NULL,
    PRIMARY KEY ( geo_id )
);

INSERT INTO `geo`(`lng`, `lat`, `name`) VALUES (118.302416,33.958887,"实验小学");
INSERT INTO `geo`(`lng`, `lat`, `name`) VALUES (118.303997,33.95188,"宿迁市人民医院");
INSERT INTO `geo`(`lng`, `lat`, `name`) VALUES (118.302991,33.935828,"宿迁学院");
INSERT INTO `geo`(`lng`, `lat`, `name`) VALUES (118.28215,33.959307,"金陵名府");
INSERT INTO `geo`(`lng`, `lat`, `name`) VALUES (118.290081,33.925404,"润园");
INSERT INTO `geo`(`lng`, `lat`, `name`) VALUES (118.354751,33.959007,"国际馆");

下面是google给的解决方案（基于公里km）。

SELECT
  geo_id, `name`,(
    6371 * acos (
      cos ( radians(33.958887) )
      * cos( radians( lat ) )
      * cos( radians( lng ) - radians(118.302416) )
      + sin ( radians(33.958887) )
      * sin( radians( lat ) )
    )
  ) AS distance
FROM geo
HAVING distance < 20
ORDER BY distance
LIMIT 0 , 20;

其中33.958887是纬度，118.302416是经度。

详情代码：

/** 附近的商家 */
public function get_near_business() {
        if (!$this->validate->validate('lng', ['require','regex|-?((0|1?[0-7]?[0-9]?)(([.][0-9]{1,4})?)|180(([.][]{1,4})?))'])) { // 经度
            $this->json->setErr(10001, '缺少lng或lng格式不正确');
            $this->json->Send();
        }
        if (!$this->validate->validate('lat', ['require','regex|-?((0|[1-8]?[0-9]?)(([.][0-9]{1,4})?)|90(([.][]{1,4})?))'])) { // 纬度
            $this->json->setErr(10001, '缺少lat或lng格式不正确');
            $this->json->Send();
        }

        if (!isset($_POST['page']) || $_POST['page'] < 1) {
            $_POST['page'] = 1;
        }
        // 分页获取附近的商家信息
        $sql_count = "SELECT  id, `name`,( 6371 * acos (
                    cos ( radians(".$_POST['lat'].") )
                    * cos( radians( lat ) )
                    * cos( radians( lng ) - radians(".$_POST['lng'].") )
                    + sin ( radians(".$_POST['lat'].") )
                    * sin( radians( lat ) )
                    )
                ) AS distance
                FROM tf_my_business
                WHERE `status` = 1
                HAVING distance < 10";
        $count = count(M()->query($sql_count));
        $hasPage = ceil($count / C('PAGE.LIMIT'));
        $hasPage = $hasPage ? $hasPage : 1;

        if ($_POST['page'] > $hasPage) {
            $this->json->setErr(10002, '页数有误');
            $this->json->Send();
        }

        $limit = (($_POST['page'] - 1) * C('PAGE.LIMIT')) . "," .C('PAGE.LIMIT');
        $sql_list = "SELECT  `id`,`name`,`info`,( 6371 * acos (
                    cos ( radians(".$_POST['lat'].") )
                    * cos( radians( lat ) )
                    * cos( radians( lng ) - radians(".$_POST['lng'].") )
                    + sin ( radians(".$_POST['lat'].") )
                    * sin( radians( lat ) )
                    )
                ) AS distance
                FROM tf_my_business
                WHERE `status` = 1
                HAVING distance < 10
                ORDER BY distance ASC
                LIMIT ".$limit;
        $datalist = M()->query($sql_list);
        if ($datalist) {
            // 处理datalist
            $my_business_img_model = M('my_business_img');
            foreach ($datalist as &$v) {
                // 获取主图
                $my_business_img_info = $my_business_img_model->where(['m_b_id'=>$v['id'],'type'=>1,'is_main'=>1])->find();
                $v['img'] = $my_business_img_info['img'];
                if (strpos($v['img'],'cdn') === false) {
                    $v['img'] = C('CDN.URI').$v['img'];
                }
            }

            $data['datalist'] = $datalist;
            $data['current_page'] = $_POST['page'];
            $data['hasPage'] = $hasPage;
            $this->json->setErr(0, '获取成功');
            $this->json->setAttr('data',$data);
            $this->json->Send();
        } else {
            $this->json->setErr(10003, '暂无数据');
            $this->json->Send();
        }
}

{
    "errno": 0,
    "errdesc": "获取成功",
    "timestamp": 1524749336,
    "data": {
        "datalist": [
            {
                "id": "3",
                "name": "京东",
                "info": "京东",
                "distance": "4.665364145881758",
                "img": "https://cdn.caomall.net/1524732806744365022.png"
            }
        ],
        "current_page": "1",
        "hasPage": 1
    }
}