Get integer value from MySQL database [closed]

I assume you'll first want to authenticate your user. You can use any number of available libraries for that or roll your own. Here are a few places to start:

• php sessions to authenticate user on login form
• http://pear.php.net/package/Auth/redirected

Once you have the user_id of the user who is authenticated you can build a very simple MySQL query to extract the credits:

// Connect to the database
$connection = new mysqli("localhost", "mysql_user", "mysql_password", "database");
if (mysqli_connect_errno())
{
    printf("Connect failed: %s\n", mysqli_connect_error());
    exit();
}

if ($statement = $mysqli->prepare("SELECT credits FROM user WHERE user_id=?"))
{
    // $user_id is the stored value
    $statement->bind_param("i", $user_id);
    $statement->execute();
    $statement->bind_result($credits);
    $statement->fetch();

    echo "User has " . $credits . "credits<br/>";

    $statement->close();
}

/* close connection */
$connection ->close();

Code mostly copy/pasted from http://www.php.net/manual/en/mysqli.prepare.php

if you know user_id, username or email of currently logged in user your SQL-queries would be:

"SELECT `credits` FROM `users` WHERE `user_id` = '$user_id'"
"SELECT `credits` FROM `users` WHERE `username` = '$username'"
"SELECT `credits` FROM `users` WHERE `email` = '$email'"

I assumed your users-table named "users"

Not quite sure about this, since I usually work with PDO, but I guess it should be fine for the beginning

<?php
$db = mysql_connect("localhost", "user", "password");

$sql = "SELECT credits FROM users WHERE user_id = " . mysql_real_escape_string($_SESSION['userid']);

$result = mysql_query($sql);

$row = mysql_fetch_object($result);

$credits = $row->credits;

echo $credits;