editarcoche.php

<?php
$servername = "localhost";
$username = "root";
$password = "";
$conn = mysqli_connect($servername, $username, $password, "coche");
if ($_SERVER['REQUEST_METHOD'] === 'POST')
{

    if (isset($_POST["marca"]))
    {
        $sql = "UPDATE `coche`.`coche` SET `marca`='".$_POST["marca"]."' WHERE  `id`=" . $_GET['id'] . ";";
        mysqli_query($conn, $sql);
    }
    if (isset($_POST["modelo"]))
    {
        $sql = "UPDATE `coche`.`coche` SET `modelo`='".$_POST["modelo"]."' WHERE  `id`=" . $_GET['id'] . ";";
        mysqli_query($conn, $sql);
    }
    if (isset($_POST["foto"]))
    {
        $sql = "UPDATE `coche`.`coche` SET `foto`='".$_POST["foto"]."' WHERE  `id`=" . $_GET['id'] . ";";
        mysqli_query($conn, $sql);
    }
    header('Location: '. "/listarcoches.php");
}
?>

<!DOCTYPE html>
<html>
    <head>
        <title>Editar coche</title>
        <meta charset="UTF-8">
    </head>
    <body>
    <form action="#" method="POST">
        <?php

        if ($_SERVER['REQUEST_METHOD'] === 'GET')
        {
            if (isset($_GET['id']))
            {
                $sql = "SELECT * from COCHE WHERE id = \"" . $_GET['id'] . "\"";
                $res = mysqli_query($conn, $sql);
                while ($arr = mysqli_fetch_array($res,MYSQLI_ASSOC))
                {
                    foreach($arr as $key=>$valor) {
                        if (($key == "marca")||($key == "modelo")||($key == "foto"))
                        echo "<input name=\"".$key."\" type=\"text\" value=\"" . $valor . "\"></td>";
                        if ($key == "foto")
                        echo "<img src=\"" . $valor . "\">";
                    }
                    echo "<a href=\"borrarcoche.php?id=" . $_GET["id"] . "\">Borrar</a>";

                }
            }
        }

        ?>
        <input type="submit" value="Buscar">
    </from>
    </body>
</html>