PHP 脚本未正确从 MySQL 数据生成 KML 文件 - 如何正确处理此问题？

Posted 2023-02-23

【中文标题】PHP 脚本未正确从 MySQL 数据生成 KML 文件 - 如何正确处理此问题？

【英文标题】：PHP Script not generating KML file from MySQL data properly - how to correctly approach this?

【发布时间】：2014-12-11 00:41:09

【问题描述】：

我有一个 php 脚本，它应该将 mysql 中的所有位置输出到一个名为 allUsers.kml 的文件中。 创建时文档是空的，它看起来像这样：

<?xml version="1.0" encoding="UTF-8"?>
<kml xmlns="http://www.opengis.net/kml/2.2">
  <Document/>
</kml>

KML 应包含用户、位置和运动列表，如下所示：

<?xml version="1.0" encoding="UTF-8"?>
<kml xmlns="http://www.opengis.net/kml/2.2">
<Document>
<Placemark>
    <name>Anthony</name>
    <userid>1899136</userid>
    <sports>Running</sports>
    <Point>
        <coordinates>-2.799667,54.04569</coordinates>
    </Point>
</Placemark>
</Document>
</kml>

但事实并非如此。

如何修复我的 php 以正确输出此文档？

<?php
    header("Access-Control-Allow-Origin: *");
    $con=mysql_connect(PARAMS);

    mysql_select_db("db");
    $user = $_POST['user'];
    $lat = $_POST['lat'];
    $lon = $_POST['lon'];

    $sql = "UPDATE userActivityLocation SET lat='$lat', lon='$lon' WHERE user='$user'";
    $result=mysql_query($sql);
    echo $result;
    if (!mysql_query($sql, $con)) 
        die('Error: ' . mysql_error());
     else 
        echo "Added";
       mysql_close($con);

    $sql2="SELECT * FROM userActivityLocation";
    $result2=mysql_query($sql2);

    $dom = new DOMDocument('1.0', 'UTF-8');
    $dom->formatOutput = true;
    // Iterate through the rows, adding KML nodes for each
    // Creates the root KML element and appends it to the root document.
    $node = $dom->createElementNS('http://www.opengis.net/kml/2.2', 'kml');
    $parNode = $dom->appendChild($node);

    // Creates a KML Document element and append it to the KML element.
    $dnode = $dom->createElement('Document');
    $docNode = $parNode->appendChild($dnode);


    while ($row = mysql_fetch_assoc($result2))
        $dnode = $dom->createElement("Placemark");
        $newnode = $docNode->appendChild($dnode);

        $newnode = $dom->createElement("user");
        $newnode->nodeValue = $row['user'];
        $dnode->appendChild($newnode);

        $newnode = $dom->createElement("sports");  
        $newnode->nodeValue = $row['sports'];
        $dnode->appendChild($newnode);

        //Coordinates are a child node of the 'Point' node       
        $pointnode = $dom->createElement("Point");
        $dnode->appendChild($pointnode);

        $coordsnode = $dom->createElement("coordinates");
        $coordsnode->nodeValue = $row['lon'].",".$row['lat'];
        $pointnode->appendChild($coordsnode);
    

    $filename = "allUsers.kml";
    $dom->save($filename);
    $msg = "PHP Working - Location - KML Generated";
    echo $msg;
    echo "#####";
    echo $filename;
?>

我真的非常感谢任何帮助。谢谢。

【参考方案1】：

看起来您在“添加”之后关闭了 SQL 连接，因此您的选择查询没有得到任何结果。

   else 
    echo "Added";    
     mysql_close($con);  

  $sql2="SELECT * FROM userActivityLocation";  
  $result2=mysql_query($sql2);  

将mysql_close($con); 移到文件的最底部，这样就可以了。