How to access specific mySQL data rows and columns after logging in? - php

Question

This script below is what I'm using to check to see if the user name and password is in my database. This is fine, what I want is now to stay within the row that username and password is found in. In the same row under different columns is more information about the user. I would like to display some of this information in various divs. Not all of it. Examples of the columns other than Password and Email would be "FirstName" and "LastName"
There is also an "Id" column it would be great to be able to do something like "you are logged in, you are Id 10101 and then display FirstName and LastName from current Id.
<?
session_start();
//then do rest of the stuffs//
?>
<?php
if (!isset($_POST['submit'])){
?>
<!-- The HTML login form -->
<form action="<?=$_SERVER['PHP_SELF']?>" method="post">
Email: <input type="text" name="Email" /><br />
Password: <input type="password" name="Password" /><br />
<input type="submit" name="submit" value="Login" />
</form>
<?php
} else {
require_once("db_const.php");
$mysqli = new mysqli(DB_HOST, DB_USER, DB_PASS, DB_NAME);
# check connection
if ($mysqli->connect_errno) {
echo "<p>MySQL error no {$mysqli->connect_errno} : {$mysqli->connect_error}</p>";
exit();
}
$Email = $_POST['Email'];
$Password = $_POST['Password'];
$sql = "SELECT * from stores_db WHERE Email = '{$Email}' AND Password = '{$Password}' LIMIT 1";
$result = $mysqli->query($sql);
if (!$result->num_rows == 1)
{
echo "<p>Invalid Email or Password combination</p>";
}
else
{
$recordset = mysqli_fetch_array($result);
$temp_firstname=$recordset['FirstName'];
$temp_lasttname=$recordset['LastName'];
$temp_id=$recordset['Id'];
$_SESSION['user_id']=$temp_id;
header("location:homepage.php"); // direct to your page to show
}
}
?>
Code on homepage.php
<?php
session_start(); echo $_SESSION['user_id']; //to display the id of the logged in user
?>

Answer 1

$sql = "SELECT * from stores_db WHERE Email LIKE '{$Email}' AND Password LIKE '{$Password}' LIMIT 1";
$result = $mysqli->query($sql);
if (!$result->num_rows == 1)
{
echo "<p>Invalid username/password combination</p>";
}
else
{
echo "<p>Logged in successfully</p>";
$recordset = mysqli_fetch_array($result);
$temp_firstname=$recordset['FirstName'];
// storing firstname on a variable
$temp_lasttname=$recordset['LastName'];
$temp_id=$recordset['id'];
$_SESSION['user_id']=$temp_id;
header("location:homepage.php"); // direct to your page to show
}
After Doing this,
write
session_start();
echo $_SESSION['user_id']; //to diplay the id of the logged in user
in the page to be foolowed

Answer 2

"Headers already sent" means that your PHP script already sent the HTTP headers, and as such it can't make modifications to them now.Check that you don't send ANY content before calling session_start. Better yet, just make session_start the first thing you do in your PHP file (so put it at the absolute beginning, before all HTML etc).
<?
session_start();//at the top most
//then do rest of the stuffs//
?>

Answer 3

<?
session_start();
if (!isset($_POST['submit'])){
?>
<!-- The HTML login form -->
<form action="<?=$_SERVER['PHP_SELF']?>" method="post">
Email: <input type="text" name="Email" /><br />
Password: <input type="password" name="Password" /><br />
<input type="submit" name="submit" value="Login" onclick="" />
</form>
<?php
} else {
require_once("db_const.php");
$mysqli = new mysqli(DB_HOST, DB_USER, DB_PASS, DB_NAME);
# check connection
if ($mysqli->connect_errno) {
echo "<p>MySQL error no {$mysqli->connect_errno} : {$mysqli->connect_error} </p>";
exit();
}
$Email = $_POST['Email'];
$Password = $_POST['Password'];
$sql = "SELECT * from stores_db WHERE Email = '{$Email}' AND Password = '{$Password}' LIMIT 1";
$result = $mysqli->query($sql);
if (!$result->num_rows == 1)
{
echo "<p>Invalid Email or Password combination</p>";
}
else
{
$recordset = mysqli_fetch_array($result);
$temp_firstname=$recordset['FirstName'];
$temp_lasttname=$recordset['LastName'];
$temp_id=$recordset['Id'];
$_SESSION['user_id']=$temp_id;
$_SESSION['lastname']=$temp_lasttname;
$_SESSION['firstname']=$temp_firstname;
header("location:homepage.php"); // direct to your page to show
}
}
?>
Code on homepage.php
<?php
session_start(); echo $_SESSION['user_id']; //to display the id of the logged in user
?>