Untitled

<html>
    <head>
    <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-alpha.6/css/bootstrap.min.css" integrity="sha384-rwoIResjU2yc3z8GV/NPeZWAv56rSmLldC3R/AZzGRnGxQQKnKkoFVhFQhNUwEyJ" crossorigin="anonymous">
    </head>
    <body>
        <button><a href="elimina.php">ELIMINA VISITE</a></button><br>
        <button><a href="logout.php">LOGOUT</a></button><br>
    </body>
</html>
<?php
 session_start();
    echo "Pagina dell'admin<br>";
    echo "Qui puoi inserire le visite<br>";
    $hostname="localhost";
    $username="root";
    $password="";
    $db="sitomedico";
    $connessione=mysqli_connect($hostname, $username, $password, $db) or die("Errore di connessione<br>");

    $strSQL="SELECT * FROM visite";
    $query=mysqli_query($connessione, $strSQL);
    if(!$query){
        echo "Errore nella query";
        exit();
    }
    echo"Queste sono le visite già presenti";
    $riga= mysqli_fetch_array($query);
    echo('<table border=1>');
    echo('<tr>
           <th>N. Visita</th>
           <th>Data</th>
           <th>Ora</th>
           <th>Note</th>
           <th>Effettuata</th>
           <th>Id Paziente</th>
           <th>Id Medico</th>
           <th>Id Prestazione</th>
        </tr>');

    while($riga){
        echo("<tr>");
        echo("<td>".$riga["num_vis"]."</td>");
        echo("<td>".$riga["data"]."</td>");
        echo("<td>".$riga["ora"]."</td>");
        echo("<td>".$riga["note"]."</td>");
        echo("<td>".$riga["effettuata"]."</td>");
        echo("<td>".$riga["id_paz"]."</td>");
        echo("<td>".$riga["id_med"]."</td>");
        echo("<td>".$riga["id_pre"]."</td>");
        echo("</tr>");
        $riga=mysqli_fetch_array($query);
    }

    $pazienti="Select id_paz from pazienti";
    while($row=mysqli_fetch_assoc($query))
    echo("ciao <select name='paziente' action='post'>
            <option value=".$pazienti['id_paz']."></option>
        </select>");