SilverStripe ORM中每个mysql的位置Y周围半径X内的位置

Question

我在 SilverStripe 3.4.0 中每个 mysql 过滤位置 Y 周围半径 X 内的位置。

到目前为止，我已经实现了一个原始查询来获取圆圈中的 ID，而不是使用它们来过滤每个 SilverStripe ORM，因为我必须根据多个条件进行过滤，而地理过滤器只是其中之一。

另请参阅 Google 的“商店定位器”示例： https://developers.google.com/maps/articles/phpsqlsearch_v3

$searchDistance = '...';
$searchLat = '...';
$searchLng = '...';

$geolimitedIDs = DB::query('SELECT id, (6371 * acos(cos(radians('.$searchLat.')) * cos(radians(Latitude)) * cos( radians(Longitude) - radians('.$searchLng.')) + sin(radians('.$searchLat.')) * sin(radians(Latitude))))
    AS distance
    FROM "DataObject"
    HAVING distance < ' . $searchDistance . '
    ORDER BY distance')->column();

if($geolimitedIDs) {
    $DataObjects = $DataObjects->filter(array(
        'ID' => $geolimitedIDs
    ));
}

在 _config 中，我创建了 DataObject-Tabel MyISAM

DataObject:
  create_table_options:
    MySQLDatabase:
      'ENGINE=MyISAM'

这会提供所需的结果，但需要额外的查询。 是否可以将地理过滤器直接添加到 ORM 中的查询中？

Answer 1

我不确定您所说的“直接在 ORM 中查询”是什么意思，但如果理解为“不调用 Web 服务”，那么我可以提供以下解决方案...

请注意，我建议使用 javascript 直接在商店定位器中使用谷歌地图执行此操作，以便通过 javascript 同步完成计算。

function FilterMemberByPostCodeDistance($params, $query){
    $query->where('Member.PostCode IS NOT NULL')
        ->innerJoin('PostCodeToLocation',"SUBSTRING_INDEX(SUBSTRING_INDEX(Member.PostCode,' ', 1),' ',-1) = PostCodeToLocation.OutCode");
 
    $latitude = (float)$postCodeToLocation->Latitude;
    $longitude = (float)$postCodeToLocation->Longitude;
 
    $fTemp = floatval($params['Distance']) / 111.045;
    $fMagicSquareMinLatitude = $latitude - $fTemp;
    $fMagicSquareMaxLatitude = $latitude + $fTemp;
 
    $fTemp = 50.0 / (111.045 * cos(deg2rad($latitude)));
    $fMagicSquareMinLongitude = $longitude - $fTemp;
    $fMagicSquareMaxLongitude = $longitude + $fTemp;
 
    $query->where(
        //Magic Square - this is a simple square to filter out most out of distance values before the magic circle
        //this is done because the circle calculation is much more expensive that the square
 
        'PostCodeToLocation.Latitude  BETWEEN '.$fMagicSquareMinLatitude.' AND '.$fMagicSquareMaxLatitude.'
            AND PostCodeToLocation.Longitude BETWEEN '.$fMagicSquareMinLongitude.' AND '.$fMagicSquareMaxLongitude
 
        //Magic Circle (https://en.wikipedia.org/wiki/Haversine_formula)
        //This is what does the complicated maths to determine if the postcode is in the cirectle or not
        //not as we are using out codes only, this is a "good estimate" but not 100% accurate
 
        //.' AND acos(sin(RADIANS('.$latitude.'))
        //  * sin(RADIANS(PostCodeToLocation.Latitude))
        //  + cos(RADIANS('.$latitude.'))
        //  * cos(RADIANS(PostCodeToLocation.Latitude))
        //  * cos(RADIANS(PostCodeToLocation.Longitude)
        //  - (RADIANS('.$longitude.'))))
        //  * 6371 <= '.($params['Distance'] * 1.60934) //Kilometers
 
        //REFACTOR of above to process more upfront within PHP
        .' AND acos(sin('.deg2rad($latitude).')
           * sin(RADIANS(PostCodeToLocation.Latitude)) + '.cos(deg2rad($latitude))
        .' * cos(RADIANS(PostCodeToLocation.Latitude))
           * cos(RADIANS(PostCodeToLocation.Longitude) - '.deg2rad($longitude).'))
           * 6371 <= '.($params['Distance'] * 1.60934) //Kilometers
    );
    return $query;
}

上面的函数使用邮政编码从公开数据中获取 lon/lat 对（此位仅适用于英国）。

class PostCodeToLocation extends DataObject{

    static $db = array(
        'OutCode'       => 'Varchar(5)',
        'Latitude'      => 'Float',
        'Longitude'     => 'Float'
    );
 
    public static $indexes = array(
        'OutCode'           => true
    );
 
    public function PopulatePostCodeToLocationTable() {
 
        DB::query('TRUNCATE TABLE PostCodeToLocation');
 
        $arrPostCodetoLocations = file(BASE_PATH .'/mysite/.../postcode_outcode_to_latlong.csv');
        if(!empty($arrPostCodetoLocations))
            foreach ($arrPostCodetoLocations as $strPostCodetoLocation) {
                list ($strOutCode,$strLatitude,$strLongitude) = explode(',',$strPostCodetoLocation);
                DB::query("INSERT INTO PostCodeToLocation (OutCode, Latitude, Longitude )
                    VALUES ('".$strOutCode."','".$strLatitude."','".$strLongitude."')"
                );
            }
    }
}

上面的数据文件在here找到。

Answer 2

是的，可以使用 ORM 来实现这一点。您可以将DataQuery 拉出DataList，更改它（添加子句等），然后用它更新DataList。

类似：

$dataList = MyObject::get();

$dataQuery = $dataList->dataQuery();

$dataQuery->where(...);
$dataQuery->having(...);

$dataList->setDataQuery($dataQuery);

添加和别名选择有点棘手，因为您需要根据DataQuery 修改SQLQuery，但它也应该是可能的，尽管只需添加haversin 公式作为排序将起作用。

$dataList->sort(...)