CODEWITHSUNDEEP
javascriptphpmysqlsession
Jack
Jack

Reputation: 77

how to turn a php session into a usable variable

i have created a site were i have 2 tables on a database. the first page has 2 links which when clicked sends the name of the link to a php session. it then takes you to a page were its meant to view ether one of the databases based on the data that has been saved In the php session.

what i am trying to achieve is to have those links open up the table inside that file that will open up when the link is clicked. i don't want to make a new .php file for every table since i want to be able to simply add and access those tables on one document but not more then one.

that is my problem. on that document were it sends me to access the table from my database i want to access in variable (code below). the code below will explain what i need to know.

this is the code which i view the data in my table

 $servername = "localhost";
    $username = "root";
    $password = "root";
    $dbname = "myDB";


    $conn = new mysqli($servername, $username, $password, $dbname);

    if ($conn->connect_error) {
         die("Connection failed: " . $conn->connect_error);
    } 

    $sql = "SELECT id, firstname, lastname FROM tablenamehere  ORDER BY id DESC LIMIT 500";
    $result = $conn->query($sql);

    if ($result->num_rows > 0) {

         while($row = $result->fetch_assoc()) {
             echo "<p>". $row["firstname"]. " " . $row["lastname"] . "</p>";
         }
    } else {
         echo "0 results";
    }

    $conn->close();

> the code below is were i want to have the variable that has the name of the link i clicked on the page which gets redirected to this when the link is clicked. the variable that i gather from the php session i want to appear at the tablenamehere text.

 $sql = "SELECT id, firstname, lastname FROM tablenamehere  ORDER BY id DESC LIMIT 500";
    $result = $conn->query($sql);

the code i have so far which creates the php session but is not connected to links yet are below.

<html>
<body>
<a href="test1.php?a=newtable">Register Now!</a>
</body>
</html>
<?php

session_start();
?>

<?php
 if(isset($_GET['a'])){
    $_SESSION['link']=$_GET['a'];
 }

 echo "the veriable is " . $_SESSION['link'] . "<br>";

i only want multiple tables to open up in this one php file. thank you for helping, any questions please message below.

Upvotes: 1

Views: 117

Answers (2)

hherger
hherger

Reputation: 1680

My guess: the script that accesses the database is test1.php. The link adds already the call parameter a (=newtable):

<a href="test1.php?a=newtable">Register Now!</a>

The script test1.php could honor this $_GET parameter like you do when setting the $_SESSION parameter. The modification of your code would then look like this:

$servername = "localhost";
$username = "root";
$password = "root";
$dbname = "myDB";

$conn = new mysqli($servername, $username, $password, $dbname);

if ($conn->connect_error) {
     die("Connection failed: " . $conn->connect_error);
} 

// Get and sanitize table name
$tablename = $conn->real_escape_string($_GET['a']);

$sql = "SELECT id, firstname, lastname FROM $tablename ORDER BY id DESC LIMIT 500";
$result = $conn->query($sql);

// ....

Notes:

  • In my example I assume that all tables are handled the same way. Of course, you could differentiate code based on the value of $tablename.
  • You most probably would not need a $_SESSION variable.
  • If, for any reason you must use a $_SESSION variable $_GET['a'] obviously should be overwritten by $_SESSION['link'] or vice-versa.

  • For security reasons, do not forget to sanitize the input parameter $_GET['a']!

Upvotes: 1

RiggsFolly
RiggsFolly

Reputation: 94662

If we can assume you are passing a table name as a parameter ( bit dangerous ) then you can do this

<?php

if(isset($_GET['a'])){
    $_SESSION['link']=$_GET['a'];
}


$sql = "SELECT id, firstname, lastname 
        FROM {$_SESSION['link']}
        ORDER BY id 
        DESC LIMIT 500";

But a better way might be to pass an indicator to the table you want to use. This way you are not passing a real table name around in the ether for people to see

if(isset($_GET['a'])){
    $_SESSION['link']=$_GET['a'];
}


switch ($_SESSION['link']) {
case : 'a'
    $tbl_name = 'table1';
    break;
case : 'b'
    $tbl_name = 'table2';
    break;
default:
    $tbl_name = 'default_table';
}


$sql = "SELECT id, firstname, lastname 
        FROM $tbl_name 
        ORDER BY id 
        DESC LIMIT 500";

Upvotes: 2

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