通过关联表在 Laravel 5.1 中的 POINT 按距离排序

Question

我正在尝试根据他们与用户提交的邮政编码的距离和距离来排序 events。

我附上了我的数据库 table 及其关系的示例，如您所见，geom 通过 postcode 与多个地址关联，地址可以关联到多个 table（在本例中为事件 table）。

我正在从最终用户那里获取邮政编码以及以英里为单位的半径来检索适当的事件，这是我如何在 Eloquent.

中实现此目的的示例

/**
 * Extend locale method which initially only gets lat/long for given postcode to search
 *
 * @param \Illuminate\Database\Eloquent\Builder $query The query builder
 * @param \App\Http\Requests\SearchRequest $request The search request
 * @return void
 */
protected function locale(Builder $query, SearchRequest $request)
{
    $postcode = $this->formatPostcode($request->postcode);

    $geom = Geom::query()->where('postcode', $postcode)->first();
    if (! $geom || Cache::has('postcodeAPIFailed')) {
        return;
    }

    $lat = $geom->geo_location['lat'];
    $long = $geom->geo_location['long'];

    // Top-left point of bounding box
    $lat1 = $lat - ($request->within / 69);
    $long1 = $long - $request->within / abs(cos(deg2rad($lat)) * 69);

    // Bottom-right point of bounding box
    $lat2 = $lat + ($request->within / 69);
    $long2 = $long + $request->within / abs(cos(deg2rad($lat)) * 69);

    $query->whereHas('address', function (Builder $query) use ($request, $lat, $long, $lat1, $long1, $lat2, $long2) {
        $query->whereHas('geom', function (Builder $query) use ($request, $lat, $long, $lat1, $long1, $lat2, $long2) {
            $query->whereRaw('st_within(geo_location, envelope(linestring(point(?, ?), point(?, ?))))', [$long1, $lat1, $long2, $lat2]);
        });
    });
}

在我们检索到搜索结果后，我们在控制器中计算每个结果的距离。

if ($request->has('postcode')) {
    $postcodeDistances = $this->getDistances($results, $request);
}

这会生成一个包含 key of postcode 和 value of distance 的数组，即 $postcodeDistances['L1 0AA'] = '3';，我们将此数组发送到视图。

然后在视图中，我们使用以下逻辑在适用的记录上显示距离

@if($postcodeDistances)
    <span>
        {{ $postcodeDistances[$result->address->postcode] }}
        mile{{ $postcodeDistances[$result->address->postcode] != 1 ? 's' : '' }} away
    </span>
@endif

我尝试了一些方法，但我无法更新我的 function locale() 以按距离排序。我考虑过也许我可以将距离附加到集合并使用 Laravel 方法以这种方式对集合进行排序，但是如果后者甚至可能的话，从数据库层实现这一点将是理想的。

我的第一次尝试是在 whereHas('geom') 之后添加选择距离字段并按新字段排序

$query->addSelect(\DB::raw("ST_DISTANCE_SPHERE(geo_location, POINT({$long}, {$lat})) AS distance"));

我收到以下错误：

SQLSTATE[21000]: Cardinality violation: 1241 Operand should contain 2 column(s) (SQL: select count(*) as aggregate from `event` where (select count(*) from `address` where `address`.`addressable_id` = `event`.`id` and `address`.`addressable_type` = event and (select count(*), ST_DISTANCE_SPHERE(geo_location, POINT(-2.717472, 53.427078)) AS distance from `geom` where `geom`.`postcode` = `address`.`postcode` and st_within(geo_location, envelope(linestring(point(-3.6903924055016, 52.847367855072), point(-1.7445515944984, 54.006788144928))))) >= 1) >= 1 and (select count(*) from `organisation` where `event`.`organisation_id` = `organisation`.`id` and `status` = 1) >= 1 and `event_template_id` is not null and `date_start` >= 2018-07-31 00:00:00 and `status` in (1, 5))

我也尝试在同一个地方使用 orderByRaw，虽然我没有收到错误，但结果没有相应地排序。

$query->orderByRaw('ST_DISTANCE_SPHERE(geo_location, POINT(?, ?)) ASC', [$long, $lat]);

Answer 1

我会尽力解决您的问题。但。正如我在评论中提到的，您必须将 geo_location 拆分为纬度和经度。

完成后，公式如下。这将计算以公里为单位的距离。

$distance = 50; //max distance in km
$limit = 100; //the amount of selected records
$earthRadiusKm = 6371;
$earthRadiusMiles = 3959;
$postcode = $this->formatPostcode($request->postcode);
$geom = Geom::query()->where('postcode', $postcode)->first();
$lat = $geom->lat;
$lng = $geom->lng;

//assuming your Geom model db name is geoms and the 'id' is id
$postcodeDistances = \DB::table('geoms')->selectRaw("
        geoms.id,  ( $earthRadiusKm * acos( cos( radians($lat) ) * cos( radians( geoms.lat ) ) 
        * cos( radians( geoms.lng ) - radians($lng) ) + sin( radians($lat) ) *
        sin(radians(geoms.lat)) ) ) AS distance, lat, lng
    ")->havingRaw("distance < $distance")->orderBy('distance')->limit($limit)->get();

为了您的利益，如果您想要以英制英里为单位的结果，我在两个指标中都添加了地球半径。由于该公式确实使用了地球的半径，因此距离越远越准确。

结果（json）应该是这样的（2条记录结果，第一个坐标永远是起点）。仅供参考，坐标在菲律宾。

all: [
   {#3627
     +"id": 1128,
     +"distance": 0.0,
     +"lat": "15.6672998",
     +"lng": "120.7349950",
   },
   {#3595
     +"id": 1535,
     +"distance": 9.564007130831,
     +"lat": "15.6732128",
     +"lng": "120.6458749",
   },
]

通过关联表在 Laravel 5.1 中的 POINT 按距离排序

Order by distance on POINT in Laravel 5.1 via associated tables

geometry

point

sql-order-by

eloquent

laravel-5