为每个单独的数据库记录创建链接[重复]

Question

This question already has an answer here:

• “Notice: Undefined variable”, “Notice: Undefined index”, and “Notice: Undefined offset” using PHP 28 answers

I am trying to make individual links for each individual record. I have two files:

index.php

 <?php

$connect = mysql_connect("localhost", "test", "pass");
if (!$connect) {
    die("Can not connect:" . mysql_error());
}

mysql_select_db("snippets", $connect);

$ID = ''; 
if( isset( $_GET['ID'])) {
    $ID = $_GET['ID']; 
} 


$sql = "SELECT * FROM lectures";
$myData = mysql_query($sql, $connect);

while($record = mysql_fetch_array($myData)) {
$ID = $record['ID'];
$Name = $record['Name'];

    echo "<div class=\"container\">";
    echo "<div class=\"row\">";
        echo "<div class=\"col-md-2\">";
            echo "<p>$record[ID]</p>";
        echo "</div>";
        echo "<div class=\"col-md-2\">";
            echo "<p>$record[Topic]</p>";
        echo "</div>";
        echo "<div class=\"col-md-2\">";
            echo "<p>$record[Name]</p>";
        echo "</div>";
        echo "<div class=\"col-md-2\">";
            echo "<p>$record[Attendance]</p>";
        echo "</div>";
        echo "<div class=\"col-md-2\" style=\"display:none;\">";
            echo "<p>$record[Topic]</p>";
        echo "</div>";
        echo "<div class=\"col-md-2\" style=\"\">";
            echo "<td> <a href='car.php?id=" . $ID . " '>" . $record['Name'] . "</a> </td>";
        echo "</div>";
    echo "</div>";
    echo "</div>";


}

mysql_close($connect);

?>

And car.php

<?php

$connect = mysql_connect("localhost", "test", "pass");
if (!$connect) {
    die("Can not connect:" . mysql_error());
}

mysql_select_db("snippets", $connect);



$ID = ''; 
if( isset( $_GET['ID'])) {
    $ID = $_GET['ID']; 
} 

$sql = "SELECT * FROM lectures WHERE ID = '$ID' ";
$myData = mysql_query($sql, $connect);

while($record = mysql_fetch_array($myData)) {
$ID = $record['ID'];
$Name = $record['Name'];

    echo "<div class=\"container\">";
    echo "<div class=\"row\">";
        echo "<div class=\"col-md-2\">";
            echo "<p>$record[ID]</p>";
        echo "</div>";
        echo "<div class=\"col-md-2\">";
            echo "<p>$record[Topic]</p>";
        echo "</div>";
        echo "<div class=\"col-md-2\">";
            echo "<p>$record[Name]</p>";
        echo "</div>";
        echo "<div class=\"col-md-2\">";
            echo "<p>$record[Attendance]</p>";
        echo "</div>";
        echo "<div class=\"col-md-2\" style=\"display:none;\">";
            echo "<p>$record[Topic]</p>";
        echo "</div>";

    echo "</div>";
    echo "</div>";


}

mysql_close($connect);

?>

When I click on the link, the page is empty. If I put a value (eg: 2) in ID = '2', it works. But this will be the value for all links.

</div>

Answer 1

if you work in linux you should write your ID param in capital case, so you should replace this:

echo "<td> <a href='car.php?id=" . $ID . " '>" . $record['Name'] . "</a> </td>";

by this:

echo "<td> <a href='car.php?ID=" . $ID . " '>" . $record['Name'] . "</a> </td>";