php根據經緯度排序，根據經緯度篩選距離段

SQL 語句：select location.* from (select *,round(6378.138*2*asin(sqrt(pow(sin( (36.668530*pi()/180-px_lat*pi()/180)/2),2)+cos(36.668530*pi()/180)*cos(px_lat*pi()/180)* pow(sin( (117.020359*pi()/180-px_lon*pi()/180)/2),2)))*1000)  as distance from bsx_training where (px_state = 1) and (type_id != '') and (((px_lat >= 27.683290277922) and (px_lat <= 45.653769722078)) and ((px_lon >= 105.81826766053) and (px_lon <= 128.22245033947))) order by  distance limit 0,10) location  where (1=1) and (location.distance <= 500)
先忽略上面這條SQL語句。一一解釋
根據SQL排序的SQl語句

// lon1當前用戶經度 lat1當前用戶緯度，lon2 sql的經度字段 lat sql的緯度字段
function distance_sql($lon1,$lat1,$lon2,$lat2)
{
    $sql = "round(6378.138*2*asin(sqrt(pow(sin( ({$lat1}*pi()/180-{$lat2}*pi()/180)/2),2)+cos({$lat1}*pi()/180)*cos({$lat2}*pi()/180)* pow(sin( ({$lon1}*pi()/180-{$lon2}*pi()/180)/2),2)))*1000) ";
     return $sql;
}

這是一個生成根據SQL排序函數代碼

接下來下面是設置經緯度范圍內的數據

// 當前登錄用戶經緯度
if(I("post.location")){
            // 用戶經緯度
            $location = explode(",",I("post.location"));
            $userLon = $location[0];
            $userLat = $location[1];
            // 經緯距離篩選篩選
            $location = getAround($userLat,$userLon,1000000);
            $wheres1.=" and (((px_lat >= {$location["minLat"]}) and (px_lat <= {$location['maxLat']})) and ((px_lon >= {$location['minLng']}) and (px_lon <= {$location['maxLng']})))";
             // 經緯度距離優先排序，距離最近優先顯示
            if(I("post.distance_sort")){
                $distanceSql = ",".distance_sql($userLon,$userLat,"px_lon","px_lat")." as distance";
                $orderBy = " distance";
            }
            if(I("post.km")){
　　　　　　　　$kmStr = I("post.km");
　　　　　　　　// 距離 1千米-1萬米之前
               // $kmStr = "1000,10000";
　　　　　　　　
　　　　　　　　// 距離小於1千米
　　　　　　　　　　//$kmStr = "<1000";
　　　　　　　　　　　//距離大於1千米
　　　　　　　　//$kmStr = ">1000";
                if(strpos($kmStr,"<") !== false){
                    $km = explode("<",$kmStr);
                    $wheres2 .= " and (location.distance <= {$km[1]})";
                }else if(strpos($kmStr,"-") !== false){
                    $km = explode("-",$kmStr);
                    $wheres2 .= " and ((location.distance >= {$km[0]}) and (location.distance <= {$km[1]}))";
                 }else if(strpos($kmStr,">") !== false){
                    $km = explode(">",$kmStr);
                    $wheres2 .= " and (location.distance >= {$km[1]})";
                }
            }
        }

下面算出經緯度范圍內的數據控制函數

/**
 * 
 * @param  $latitude    緯度    
 * @param  $longitude    經度
 * @param  $raidus        半徑范圍(單位：米)
 * @return multitype:number
 */
function getAround($latitude,$longitude,$raidus)
{
    $PI = 3.14159265;
    $degree = (24901*1609)/360.0;
    $dpmLat = 1/$degree;
    $radiusLat = $dpmLat*$raidus;
    $minLat = $latitude - $radiusLat;
    $maxLat = $latitude + $radiusLat;
    $mpdLng = $degree*cos($latitude * ($PI/180));
    $dpmLng = 1 / $mpdLng;
    $radiusLng = $dpmLng*$raidus;
    $minLng = $longitude - $radiusLng;
    $maxLng = $longitude + $radiusLng;
    return array (minLat=>$minLat, maxLat=>$maxLat, minLng=>$minLng, maxLng=>$maxLng);
}

要實現根據經緯度排序

就直接調用distance_sql(lon1,lat1,lon2,lat2)傳入參數 並且as 一個別名例如 as distance， 然后sql語句中 order by 排序 根據 distance排序

如果篩選距離段 1000米-2000米的數據

那就sql語句嵌套sql 

select *.loation from (select *,round(6378.138*2*asin(sqrt(pow(sin( (36.668530*pi()/180-px_lat*pi()/180)/2),2)+cos(36.668530*pi()/180)*cos(px_lat*pi()/180)* pow(sin( (117.020359*pi()/180-px_lon*pi()/180)/2),2)))*1000) as distance) from table  location where (location.distance >= 1000) and (location.distance <= 2000))

如果實現根據最近位置排序sql

select *,round(6378.138*2*asin(sqrt(pow(sin( (36.668530*pi()/180-px_lat*pi()/180)/2),2)+cos(36.668530*pi()/180)*cos(px_lat*pi()/180)* pow(sin( (117.020359*pi()/180-px_lon*pi()/180)/2),2)))*1000) as distance order by distance 

 

 public function training_list()
    {
        $wheres1 = "(px_state = 1)";
        $wheres2 = " where (1=1)";
  
        $orderBy = " px_id desc";
        if(I("post.location")){
            // 用戶經緯度
            $location = explode(",",I("post.location"));
            $userLon = $location[0];
            $userLat = $location[1];
            // 經緯度篩選
            $location = getAround($userLat,$userLon,1000000);
            $wheres1.=" and (((px_lat >= {$location["minLat"]}) and (px_lat <= {$location['maxLat']})) and ((px_lon >= {$location['minLng']}) and (px_lon <= {$location['maxLng']})))";
             // 經緯度距離篩選
            if(I("post.distance_sort")){
                $distanceSql = ",".distance_sql($userLon,$userLat,"px_lon","px_lat")." as distance";
                $orderBy = " distance";
            }
            if(I("post.km")){
                $kmStr = htmlspecialchars_decode(I("post.km"));
                if(strpos($kmStr,"<") !== false){
                    $km = explode("<",$kmStr);
                    $wheres2 .= " and (location.distance <= {$km[1]})";
                }else if(strpos($kmStr,"-") !== false){
                    $km = explode("-",$kmStr);
                    $wheres2 .= " and ((location.distance >= {$km[0]}) and (location.distance <= {$km[1]}))";
                 }else if(strpos($kmStr,">") !== false){
                    $km = explode(">",$kmStr);
                    $wheres2 .= " and (location.distance >= {$km[1]})";
                }
            }
        }
        
     
     
     
      $showNum = 10;
        if(I("post.page")){
            $page = I("post.page");
        }else{
            $page = 1;
        }
        $n = ($page-1)*$showNum;
        $field = "*{$distanceSql}";
        $sql = "select location.* from (select {$field} from bsx_training where {$wheres1} order by {$orderBy} limit {$n},{$showNum}) location {$wheres2}";
        $training = M()->query($sql);
        
       
        dump(M()->getlastsql());die;
     
    }