Php Read SQL查询-选择2个值-对特定行值运行一些数学运算将值添加到新列？

Question

问题:我有一个我调用的SQL查询。我希望能够将其放入一个数组中( tbh我现在这样做了)，然后从每一行中拉出一个特定值，运行一些数学运算(我有这个)，然后将这个数学运算的结果添加到查询的末尾(或开头)的值中，然后在相同的数组或新的数组中提供该值。

这是为了计算出构成SQL查询一部分的当前位置，然后计算出每个事件(每行一个)到该位置的距离。

SQL Query ->检查事件位置->运行距离当前位置上的数学到事件->重新编译为数组(SQL Query + Distance)，准备json输出。

我要补充的是，我已经成功地在xml输出输出中做到了这一点，但当涉及到操作数组时，我仍然是一个新手……

谢谢

Terran

    // Connect to database server   
$con = mysql_connect($config_databaseServer,$config_databaseUsername,$config_databasePassword) or die(mysql_error());
mysql_select_db($config_databaseName, $con);    

// Access tables    
$sql = "SELECT * FROM " . $config . " WHERE LAT <" . $toplat . " AND LAT > " . $bottomlat . " AND LONG > " . $leftlon . " AND LONG < " . $rightlon . " AND VALIDPERIOD_STARTOFPERIOD < '" . $nowtime . "' AND VALIDPERIOD_ENDOFPERIOD > '" . $nowtime ."')";

// Execute query
$result = mysql_query($sql) or die(mysql_error());

$lata = $latitude;
$lona = $longitude;
    // Need to populate these from each row values in the query
$latb = $sqllat;
$lonb = $sqllong;                   
// need to place this in to a colum at the end of each row
    $distancefromevent = coordDistance($lata, $longa, $latb, $lonb, "m");

    // need to reform all the above so I can carry on and use the code that follows


$responses = array();
if(mysql_num_rows($result)) {
  while($response = mysql_fetch_assoc($result)) {
    $responses[] = array('dataitem'=>array_map('utf8_encode',$response));
  }
}

header('Content-type: application/json');
$json = json_encode(array($config_datexdeftype=>$responses));

$callback = $_GET[callback];
echo $callback . '(' . $json . ')';

};

return TRUE;

Answer 1

想要使用SQL查询计算位置(纬度、经度)之间的距离吗？

如果是，则是这样的：https://developers.google.com/maps/articles/phpsqlsearch?hl=hu-HU

Answer 2

这应该是可行的。

请注意，为了提高可读性，一些较长的代码已替换为[...]。

// Connect to database server   
$con = mysql_connect([...]) or die(mysql_error());
mysql_select_db($config_databaseName, $con);    

// Access tables    
$sql = "SELECT * FROM " . $config . " WHERE [...]";

// Execute query
$result = mysql_query($sql) or die(mysql_error());

// Prepare the loop
$lata = $latitude;
$lona = $longitude;
$responses = array();

// Loop over each records (stay correct even if there is no record)
while($response = mysql_fetch_assoc($result)) {
    // we assume that latitude and longitude are given by
    //  columns 'lat' and 'lon' in the SQL query.
    $latb = $response['lat']; 
    $lonb = $response['lon'];
    $distancefromevent = coordDistance($lata, $longa, $latb, $lonb, "m");
    $response['distance'] = $distancefromevent;
    $responses[] = array('dataitem'=>array_map('utf8_encode',$response));
}

header('Content-type: application/json');
$json = json_encode(array($config_datexdeftype=>$responses));

$callback = $_GET[callback];
echo $callback . '(' . $json . ')';

return TRUE;