Question

我编写的代码是在搜索到的邮政编码50英里范围内进行半径搜索。如何更改此代码以仅查找最近的诊所位置，而不是诊所位置列表？因此，如果我输入科罗拉多州丹佛的邮政编码，我的位置主要位于纽约，宾夕法尼亚州和俄亥俄州，我如何才能到达俄亥俄州最近的位置？

 /* RADIUS SEARCH - 50 MILES FROM THE ZIP CODE VARIABLE */
 $zipcode=trim($_REQUEST['zipcode']); 


 //Find Out The Longitude & Latitude of Zipcode in existing database
 $zcquery = "SELECT * FROM wp_nava5jxxyp_zipcodes WHERE zipcode = $zipcode";
    $result = mysqli_query($dbc, $zcquery);
    $row = mysqli_fetch_array($result);

     $lat = $row['latitude'];
     $long = $row['longitude'];   


 //Setting the Default Distance 50 Miles 
 // (Equation 1 / 69 = 0.0144927536231884 * 50 miles equals result below)
 $miles = 0.7246376811594203; 

   /* Query To Search for all of the Zip Codes within the range */
  $query = 'SELECT zipcode from wp_nava5jxxyp_zipcodes
  WHERE latitude between ' . $lat . ' - ' . $miles . ' and ' . $lat . ' + ' . $miles . '
   and longitude between ' . $long . ' - ' . $miles . ' and ' . $long . ' + ' . $miles;
   $result = mysqli_query($dbc, $query);  


  //Put those zip codes into a variable array
  $variabele = array();
 while($row = mysqli_fetch_array($result))
 {
 if($row['zipcode'] != '')
    $variabele[] = $row['zipcode'];
 }
 $zipcodelist =  implode(', ', $variabele); 


 // Close Connection
 mysqli_close($dbc); 

 //Query Database For Any Clinics that are included in zip code list
 $args = array(
'posts_per_page'   => 10,   
'orderby'          => 'post_title',
'order'            => 'DESC', 
'post_type' => 'clinics',
   'meta_query' => array (
        array (
          'key' => 'cliniczipcode',
          'value' => $zipcodelist,
          'compare' => 'IN'
        )
      ) );

 // the query
 $the_query = new WP_Query( $args );

Answer 1

请参阅此Fastest Way to Find Distance Between Two Lat/Long Points

基本上，您计算到基础latlon的距离，按最短距离排序，并将项目放在最顶层。如果您不想打扰复杂的查询，也可以在代码中执行此操作。

关键词是“大圆距离”和“半正式公式”

修改

假设我在洛杉矶有一个兽医诊所数据库

Limehouse Veterinary Clinic   34.1534500122    -118.3630599976
LA Pet Clinic                 34.0838623047    -118.3284454346
Bestfriends Animal Hospital   34.1692466736    -118.3970489502

我的基准坐标在好莱坞lat 34.092324，lon -118.337122

半正弦公式需要弧度而不是度数的坐标。

360度有2 pi的弧度 y弧度= 6.28319 * x度/ 360（求解y）

以下是半正式公式，其中r 2 r arcsin是地球的半径：6,371,000米

-- haversine
--                           latdif                                  londif
-- 2 r arcsin [ sqrt[  sin^2(------) + cos(lat1) * cos(lat2) * sin^2(------)   ] ]
--                            2                                       2

因此，为了获得我所在地附近最近的诊所，我可以使用此查询作为上述公式的翻译

select 
name,
2 * 6371000 * ASIN(
    sqrt(
        SIN(6.28319 * (34.092324 - lat) / 360 / 2) * SIN(6.28319 * (34.092324 - lat) / 360 / 2)
        +
        COS( 6.28319 * 34.092324 / 360  ) * COS( 6.28319 * lat / 360  )
        *
        SIN(6.28319 * (-118.337122 - lon) / 360 / 2) * SIN(6.28319 * (-118.337122 - lon) / 360 / 2)
    )
)
as dist_in_meters
from locations ORDER BY dist_in_meters;

给我

name                              dist_in_meters
LA Pet Clinic                   1234.3897096551932
Limehouse Veterinary Clinic     7204.075434291492
Bestfriends Animal Hospital    10177.689847331932

在PHP / MYSQL中找到最近的邮政编码位置

1 个答案: