CODEWITHSUNDEEP
phpmysql
Avni Mula
Avni Mula

Reputation: 11

Using PHP variables as name of table in MySQL

I want to use a PHP variable ( $username ) as the name of the SQL table I am creating. I need to use this because in my webpage each user needs to have his own table where he can put data , When I try to select the data from the table doesn't work, I have tried a lot of times but it is not working, can you help me with this problem? 

$result = mysqli_query($mysqli, "SELECT * FROM `$username` ORDER BY id DESC");

and

$sql= "SELECT * FROM `$username` ORDER BY data DESC";

Neither of these do not work , Can you please help me?

This is the code I have 

  <?php 
  session_start(); 

 if (!isset($_SESSION['username'])) {
  $_SESSION['msg'] = "You must log in first";
    header('location: login.php');
 }
 if (isset($_GET['logout'])) {
session_destroy();
unset($_SESSION['username']);
header("location: login.php");

}

$sql= 'SELECT * FROM '.$username.' ORDER BY data DESC';
  ?>
<!DOCTYPE html>
 <html>
    <head></head>
    <body>
<br/><br/>
 <div>
    <table align="center" width='100%' border=0>
        <tr bgcolor='#CCCCCC'>
            <td>Data</td>
            <td>Cantiere</td>
            <td>Pranzo</td>
            <td>Cena</td>
            <td>Hotel</td>
            <td>Macchina</td>
            <td>Note</td>
            <td>Edit/Delete</td>
        </tr>
        <?php 

         while($res = mysqli_fetch_array($result)) {         
            echo "<tr>";
            echo "<td>".$res['data']."</td>";
            echo "<td>".$res['cantiere']."</td>";
            echo "<td>".$res['pranzo']."</td>";
            echo "<td>".$res['cena']."</td>";
            echo "<td>".$res['hotel']."</td>";
            echo "<td>".$res['macchina']."</td>";    
            echo "<td>".$res['note']."</td>";
            echo "<td><a href=\"edit.php?id=$res[id]\">Edit</a> | <a 
 href=\"delete.php?id=$res[id]\" onClick=\"return confirm('Are you sure you 
want to delete?')\">Delete</a></td>";        
        }
        ?>
     </table>
 </div>

         </body>
 </html>

and i get the error :

Warning: mysqli_fetch_array() expects parameter 1 to be mysqli_result, null given in index.php on line 36

Upvotes: 1

Views: 81

Answers (4)

Martin
Martin

Reputation: 2414

You need to concatinate your variable into your select statement, i.e.

$sql="SELECT * FROM ".$username." ORDER BY id DESC";

And

$sql="SELECT * FROM ".$username." ORDER BY data DESC";

Upvotes: 0

Luca
Luca

Reputation: 288

You should try something like this:

$result = mysqli_query($mysqli, "SELECT * FROM " . $username . " ORDER BY id DESC");

Because SQL does not know what $username is

This goes for both of the query's

As suggested by Loek: Note that this answer (and the question) contain sql that easily be hijacked! Please prepare your statements before executing them!

Upvotes: 1

Ende
Ende

Reputation: 311

Try it like this

$sql= 'SELECT * FROM '.$username.' ORDER BY data DESC';

or

$result = mysqli_query($mysqli, "SELECT * FROM " .$username. " ORDER BY id DESC");

When you use a variable you need to use quotes

Upvotes: 1

Alberto
Alberto

Reputation: 1408

Try to add string concatenation:

$result = mysqli_query($mysqli, "SELECT * FROM " . $username . " ORDER BY id DESC");

and

$sql= "SELECT * FROM " . $username . " ORDER BY data DESC";

Upvotes: 0

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