MySQL：如果表中不存在变量，如何回显文本？

Question

what my code does right now is echo the links from MySQL where movie_id is equal to the GET id. what I want to add is make it echo a message like "No links were fond" if there are no links where movie_id = id

<?php
// set the _GET id

if(isset($_GET["id"])){
    $id = preg_replace('#[^a-z0-9]#i', '', $_GET['id']);
} else {
    header("location: /");
    exit(); 
}

// display data

$query = "SELECT * FROM links WHERE movie_id='$id'";
$result = mysql_query($query) or die(mysql_error());
while($row = mysql_fetch_array($result)) {

echo "<a href=\"".$row['url']."\" target=\"_blank\">link</a>";
}
?>

Answer 1

Just add a check before the while loop.

if(mysql_num_rows($result) > 0)
{

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

        echo "<a href=\"".$row['url']."\" target=\"_blank\">link</a>";
    }
}else{
    echo "No records were found.";
}

If possible, use PDO extension for database queries. http://php.net/pdo