php - 如何使用 PHP 从 url 访问 mysql 表中的字段

Question

您好，我正在尝试访问 mysql 表中的字段，结果来自 url，例如 localhost/test.php=id=2

顺便说一句，我是 xml 和 php 的菜鸟，所以请原谅我..

任何建议或教程将不胜感激..

这是我正在处理的代码

<?php
 header("Content-Type: text/xml"); 
 $xmlBody = '<?xml version="1.0" encoding="ISO-8859-1"?>';
 $xmlBody .= "<XML>";

 $dbhost = 'localhost:3036';
 $dbuser = 'nas';
 $dbpass = 'root';
 mysql_select_db('db_home') or die("no database");

 $conn = mysql_connect($dbhost, $dbuser, $dbpass) or die (mysql_error());

 $sql = mysql_query("SELECT * FROM table_gas ORDER BY datetime DESC LIMIT 0, 20");

while($row = mysql_fetch_array($sql)){

$id = $row["gas_id"]; 
$timestamp = $row["timestamp"];  
$value = $row["value"]; 
$datetime = strftime("%b %d, %Y", strtotime($row["datetime"])); 
$xmlBody .= '
<Data> 
<DataID>' . $id . '</DataID> 
<DataTime>' . $timestamp . '</DataTime>
<DataValue>' . $value . '</DataValue>
<DataTime>' . $datetime . '</DataTime>
</Data>';
} 
mysql_close(); 
$xmlBody .= "</XML>";
echo $xmlBody; 
?>

当我将它放入地址栏 local/xmltest.php?DataID=2 时，我得到一个空白屏幕..

Answer 1

首先，你不应该再使用mysql_了。我个人喜欢 PDO，所以这是我的答案

如下所述，url 应为 localhost/xmltest.php?DataID=2

header("Content-Type: text/xml");
$xmlBody = '<?xml version="1.0" encoding="ISO-8859-1"?>';
$xmlBody .= "<XML>";

$dbhost = 'localhost'; //No need to set the port if default is 3306
$dbuser = 'nas';
$dbpass = 'root';
$dbname = 'db_home';

// Check if ?id= is set or not
if ( isset($_GET['DataID']) ) {
    // Initiate the connect to the MySQL DB using PDO extention. You'll need to activate PDO if it's not done then restart Apache
    $db = new PDO('mysql:host='. $dbhost .';dbname='. $dbname, $dbuser, $dbpass);

    $query = $db->prepare("SELECT * FROM table_gas WHERE id = :id ORDER BY datetime DESC LIMIT 0, 20");
    $query->bindParam(':id', $_GET['DataID']); // Grab the value inside ?id= and pass it in the query
    $query->execute(); // Execute the query with the parameters
    $result = $query->fetchAll(); //Fetch everything and store it in a variable

    foreach ($result as $row) { // I like using foreach but while loop works too
        $xmlBody .= '
        <Data> 
        <DataID>' . $row["gas_id"] . '</DataID> 
        <DataTime>' . $row["timestamp"] . '</DataTime>
        <DataValue>' . $row["value"] . '</DataValue>
        <DataTime>' . strftime("%b %d, %Y", strtotime($row["datetime"])) . '</DataTime>
        </Data>';
    }
    $xmlBody .= "</XML>";
    echo $xmlBody; 
} else {
    echo "Invalid ID."; //Output error message if test.php?id= is not set
}