PHP e MYSQL

[Valeria89]

 <?php
require 'connessione.php';
$db_selection = mysql_select_db('db',$cn);


if($_POST && isset($_GET['ID']))
{
    aggiorna_record();
}
elseif(isset($_GET['ID']))
{
    mostra_record();
}
else
    mostra_lista();


function mostra_lista()
{
    if(isset($_GET['msg']))
        echo '<b>'.htmlentities($_GET['msg']).'</b><br /><br />';


    $query = "SELECT ID FROM tabella";


    $result = mysql_query($query);


    if (!$result) {
        die("Errore nella query $query: " . mysql_error());
    }


    echo '
    <table border="1">
        <tr>
            <th>ID</th>
            <th>&nbsp;</th>
        </tr>';


    while ($row = mysql_fetch_assoc($result))
    {
        $ID = htmlspecialchars($row['ID']);


        
        $link = $_SERVER['PHP_SELF'] . '?ID=' . $row['ID'];
echo "<tr>
                <td>$ID</td>
                <td><a href=\"$link\">VIEW</a></td>
            </tr>";
    
        
    }
echo "</table>";


    mysql_free_result($result);


    mysql_close();
}


function aggiorna_record()
{        
    //funziona
}


function mostra_record()
{
    if(isset($_GET['msg']))
        echo '<b>'.htmlentities($_GET['msg']).'</b><br /><br />';


    $ID = intval($_GET['ID']);


    $query = "SELECT tabella1.cyl, 
                    tabella2.operating_pressure
                    
            FROM     tabella1, 
                    tabella2,
                    tabella,
                    tabella3
       
            WHERE    tabella.ID = $ID AND  
                     tabella.FkEngine=tabella3.ID2 AND
                     tabella3.Fkcyl=tabella1.id AND
                     tabella3.Fkoperating_pressure=tabella2.id";


    $result = mysql_query($query);


    if (!$result) {
        die("Errore nella query $query: " . mysql_error());
    }


    if(mysql_num_rows($result) != 1) {
        die("l'ID passato via GET è errato");
    }


    list($cyl,
        $operating_pressure) = mysql_fetch_row($result);


        $cyl= htmlspecialchars($cyl);
        $operating_pressure= htmlspecialchars($operating_pressure);
        
    mysql_close();
    ?>
    <form name="form_registrazione" method="post" action="">
      <table width=”200″ border=”0″>
      <tr>
        <td>FkCyl:</td>
        <td><?php 
    include ("config.php"); 
    
    $DBName="db";


    mysql_select_db("$DBName") or die("Impossibile connettersi al database $DBName");


    //table tabella1
    $sql ="SELECT id FROM tabella2 where cyl='$cyl'";
    $r= mysql_query($sql);
    $v= mysql_fetch_array($r);
    echo "<div id=styled-select> <select name='cyl'>"; 
    echo "<option value = ".$v['id']." >$cyl</option>";
    
    $sqlquery ="SELECT id,cyl FROM tabella1";
    $result = mysql_query($sqlquery);
    
    if (!$sqlquery) {
           exit ('<p> Errore mentre recuperavo i dati' . mysql_error() . '</p>');
                }
                
     while ($value= mysql_fetch_array($result))  
   {
     echo "<option value = ".$value['id'].">".$value['cyl']."</option>"; 
   }echo "</select> </div>";
        
        ?> </td>
      </tr>
      
     </td>
        <td>Operating pressure: </td>
        <td><?php 
    $sql ="SELECT id FROM tabella2 where operating_pressure='$operating_pressure'";
    $r= mysql_query($sql);
    $v= mysql_fetch_array($r);
    echo "<div id=styled-select><select name='operating_pressure'>"; 
    echo "<option value = ".$v['id']." >$operating_pressure</option>";
    
    $sqlquery ="SELECT id,operating_pressure FROM tabella2";
    $result = mysql_query($sqlquery);
    if (!$sqlquery) {
           exit ('<p> Errore mentre recuperavo i dati' . mysql_error() . '</p>');
                }
     while ($value= mysql_fetch_array($result))  
   {
     echo "<option value = ".$value['id'].">".$value['operating_pressure']."</option>";
   }echo "</select> </div>";
        ?></td>  
      </tr>
 
     </table>
     <br> <br> 
      <p>
        <input name="invia" type="submit" value="Save" />
      </p>
    </form>


<?php
}
mysql_close();
?>

Non mi funziona questa parte:

//table tabella1
    $sql ="SELECT id FROM tabella2 where cyl='$cyl'";
    $r= mysql_query($sql);
    $v= mysql_fetch_array($r);
    echo "<div id=styled-select> <select name='cyl'>"; 
    echo "<option value = ".$v['id']." >$cyl</option>";
    
    $sqlquery ="SELECT id,cyl FROM tabella1";
    $result = mysql_query($sqlquery);
    
    if (!$sqlquery) {
           exit ('<p> Errore mentre recuperavo i dati' . mysql_error() . '</p>');
                }
                
     while ($value= mysql_fetch_array($result))  
   {
     echo "<option value = ".$value['id'].">".$value['cyl']."</option>"; 
   }echo "</select> </div>";
        
        ?> </td>
      </tr>
      
     </td>
        <td>Operating pressure: </td>
        <td><?php 
    $sql ="SELECT id FROM tabella2 where operating_pressure='$operating_pressure'";
    $r= mysql_query($sql);
    $v= mysql_fetch_array($r);
    echo "<div id=styled-select><select name='operating_pressure'>"; 
    echo "<option value = ".$v['id']." >$operating_pressure</option>";
    
    $sqlquery ="SELECT id,operating_pressure FROM tabella2";
    $result = mysql_query($sqlquery);
    if (!$sqlquery) {
           exit ('<p> Errore mentre recuperavo i dati' . mysql_error() . '</p>');
                }
     while ($value= mysql_fetch_array($result))  
   {
     echo "<option value = ".$value['id'].">".$value['operating_pressure']."</option>";
   }echo "</select> </div>";
        ?></td>  
      </tr>

in particolare queste due query:

$sql ="SELECT id FROM tabella2 where cyl='$cyl'";
$sql ="SELECT id FROM tabella2 where operating_pressure='$operating_pressure'";

non mi trova i valori di $cyl e $operating_pressure. Ho provato a stampare i valori di queste variabili e sono giusti. Quando faccio questo confronto cyl='$cyl'" non trova il record, la stessa cosa succede per operating_pressure='$operating_pressure'.

Grazie mille a tutti