CODEWITHSUNDEEP
phpsession
McDuck4
McDuck4

Reputation: 662

use session username to get data from mysql

I am making a profile page for a user on my site, where the person can change his/her information. I should be possible to change, name, lastname, username, code etc. But I have started with the username.

When a person log in, I store the username in session:

index.php

<?php
    if( !isset( $_SESSION['username'])) include('resources/auth/login.php');
            else exit( header('Location: home.php') );

                if( !isset( $_SESSION ) ) session_start();

    // Logout Session
    if( isset( $_GET['todo'] ) && $_GET['todo'] == 'logout'){

        session_unset();
        session_destroy();
        //echo 'You have been logged out!';
    }
?>

I have made a test on

profile.php:

<?php
   if( !isset( $_SESSION ) ) session_start();
?>
   <?php //echo $_SESSION['username'];?>

and this calls my username

But If I want to call the firstname from mysql database, that belongs to that username, should I use the session[username] for that? I startet to make a SQL query for it instead:

<?php
    $stmt = $mysqli->prepare("SELECT firstname FROM login");

    $stmt->execute();

    $fname = null;

      $stmt->bind_result($fname);
        while($stmt->fetch()) {
          echo $fname;
        }

    $stmt->close();
    $mysqli->close();
  ?>

This works, but calls all the firstnames in the database. So I tried to set the u_id, which is the PK in db = to stored session variable:

$stmt = $mysqli->prepare("SELECT firstname FROM login WHERE u_id=$username");

and

$stmt = $mysqli->prepare("SELECT firstname FROM loginWHERE u_id = '.$_SESSION[username]'";

But here I get an error: Undefined variable: username in profile.php

Can anybody see why that is?

Upvotes: 1

Views: 3339

Answers (2)

user5407341
user5407341

Reputation:

if i understand you well,i think this query:

$stmt = $mysqli->prepare("SELECT firstname FROM login WHERE u_id=$username");

should be this:

$stmt = $mysqli->prepare("SELECT firstname FROM login WHERE username ='.$_SESSION[username].'");
//forgive my syntax issues

if you want to retrieve the firstname of a user that is logged, the parameter for the where clause should be the the user's username as that is the only unique way to identify the user, however may i suggest you also set the id of the user in a session too, so that the where parameter now takes the user's unique id. Its a better way of making sure you retrieve information for that particular user, because two users may have the same username, so when your where clause takes that as a parameter, it retrieves two rows from the database, that will definitely cause problems.

Upvotes: 1

degers
degers

Reputation: 108

It is high propable that you didn't start the session. I only know the writing $_SESSION['username'] instead of u_id = ' . $_SESSION[username]'

Upvotes: 1

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