php mysql prepare statement not working

Question

I'm currently learning php and mysql and am trying to build an authentication webpage where the user registers and is able to log in to a member protected page. The registration process works fine but for some reason I'm getting this error in my login execution script.

Fatal error: Call to a member function prepare() on a non-object in /homepages/8/d459264879/htdocs/tymbi_reg/login_exec.php on line 40

Line 40 is here if($stmt = $mysqli->prepare("SELECT * FROM member WHERE username=? AND password =?"))

I've been trying hard to find where the problem is without any success.

This is the code that I'm using in my login script

<?php

session_start();
require_once('connection.php');
$errmsg_arr = array();
$errflag = false;
$username = $_POST['username'];
$password = $_POST['password'];

if($username == '') {
    $errmsg_arr[] = 'Username missing';
    $errflag = true;
}
if($password == '') {
    $errmsg_arr[] = 'Password missing';
    $errflag = true;
}

if($errflag) {
    $_SESSION['ERRMSG_ARR'] = $errmsg_arr;
    session_write_close();
    header("location: index.php");
    exit();
} else {


    if($stmt = $mysqli->prepare("SELECT * FROM member WHERE username=? AND password =?"))
    {
        $stmt->bind_param("ss", $username, $password);
        $stmt->execute();
        $stmt->store_results();

        if($stmt->num_rows > 0)
        {

            $SESSION['username'] = $username;
            header("Location: home.php");

        }

        else

        {

            $error['alert'] = "Username or password are incorrect";

        }

    }   

}


?>

Here's my connection.php code

<?php
$con=new mysqli("test","test","test","test");
// Check connection
if (mysqli_connect_errno())
{
echo "Failed to connect to MySQL: " . mysqli_connect_error();
}
?>

And yes, I have replaced the test values with my details

Then do u mind putting connection.php code in the question section? Let's have a look at that. — chandresh_cool, Apr 15 '13 at 12:05
if it is included, doesnt mean it works ... show that part of the code and make sure you print error if it exist. — Bojan Kovacevic, Apr 15 '13 at 12:05
You cannot use php variables like this.. is $mysqli global... ? — alwaysLearn, Apr 15 '13 at 12:06
you are using `$con` in connection.php and `$mysqli` on other page — alwaysLearn, Apr 15 '13 at 12:08
so you have $con in connection.php and use $mysqli in login script? — Bojan Kovacevic, Apr 15 '13 at 12:08
just for the same of it, can you tell me what happens when you place the content of connection.php in the code directly without the include? Are the both files in the same directory? — Cninroh, Apr 15 '13 at 12:11
I also replaced $mysqli with $con and the error now is Call to undefined method mysqli_stmt::store_results() in /homepages/8/d459264879/htdocs/tymbi_reg/login_exec.php — wannax, Apr 15 '13 at 12:14

score 1 · Answer 1 · answered Apr 15 '13 at 12:02

1

make sure you have $mysqli defined properly

$mysqli = new mysqli('host','user','pass','database_name');

answered Apr 15 '13 at 12:02

alwaysLearn

6,882
7
39
67

score 0 · Answer 2 · answered Apr 15 '13 at 12:02

0

You haven't defined $mysqli - your connection. That is why it's not working.

Unless it's defined in connection.php. Could you try var_dump $mysqli and see what you get?

answered Apr 15 '13 at 12:02

silkfire

24,585
15
82
105

score 0 · Answer 3 · answered Apr 15 '13 at 12:11

$link = mysqli_connect("localhost", "user", "my_password", "world");

/* check connection */
if (mysqli_connect_errno()) {
    printf("Connect failed: %s\n", mysqli_connect_error());
    exit();
}

this helps in reading the connection error.

or you can also use

try
{
//your connection
}catch(Exception $e)
{
  echo $e->getMessage();
}

Dieter Donnert · Answer 4 · 2016-07-08T11:38:25.237

-1

I would recommend going all-in on using the Mysqli object and not mixing in the procedural functions. You would have caught your error earlier if you had written the connection logic like so:

$con = new mysqli("host","user","pass","db");

if ($mysqli->errno)
{
    echo "Failed to connect to MySQL: " . $mysqli->error;
}

The OP declared the connection as $con and later tried to access it as $mysqli. mysqli_connect_errno() reports that $con is ok, but $mysqli->errno will fail because $mysqli is not an object at that point, because he named the the connection $con not $mysqli

edited Jul 08 '16 at 11:38

answered Jul 08 '16 at 10:41

Dieter Donnert

192
2
9

What's wrong with catching errors with mysqli_connect_errno()? Any reason it should fail the OP where your code would report? – Your Common Sense Jul 08 '16 at 10:52
It's not that it's wrong per se. It answers the wrong question. – Dieter Donnert Jul 08 '16 at 11:43

php mysql prepare statement not working

4 Answers4