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mysql – Trying to create php class for mysqli connection and use for query.

Posted by: admin July 12, 2020 Leave a comment


So I’m trying to create a class which can be used for connecting to mysql database. Should’nt be to advanced and it’s all fun and games until i try to use my class. This is my code:

the class:


class createCon  {
    var $host = 'localhost';
    var $user = 'root';
    var $pass = '';
    var $db = 'example';
    var $myconn;

    function connect() {
        $con = mysqli_connect($this->host, $this->user, $this->pass, $this->db);
        if (!$con) {
            die('Could not connect to database!');
        } else {
            $this->myconn = $con;
            echo 'Connection established!';}
        return $this->myconn;

    function close() {
        echo 'Connection closed!';



and this is where I try to query the database:


include 'connect.php';

$connection = new createCon();

$query = 'SELECT * FROM  `nickname`';
$result = mysqli_query($connection, $query);

if($numrows = mysqli_num_rows($result)) {
        echo $numrows;
    while ($row = mysqli_fetch_assoc($result)) {
        $dbusername = $row['nick'];
        $dbpassword = $row['pass'];
        echo $dbusername;
        echo $dbpassword;

I get the following errors when I try to make a query:

( ! ) Warning: mysqli_query() expects parameter 1 to be mysqli, object given in C:\wamp\www\uppgift 1 kompletering\test.php on line 13

( ! ) Warning: mysqli_num_rows() expects parameter 1 to be mysqli_result, null given in C:\wamp\www\uppgift 1 kompletering\test.php on line 15

I think i kind of understand why i get the errors, however i have no clue what so ever how to fix it. Tried a million things and nothing works. I am very new to OOP and php and would greatly appriciate some advice!

How to&Answers:

You want to pass in $connection->myconn instead of $connection. As in:

$result = mysqli_query($connection->myconn, $query);

As it stands, you’re passing in an instance of your class, rather than a mysqli, which is what the error messages are complaining about.


in database connection class you return connection. in php class you have to catch that connection variable

$connection = new createCon();
$conn = connection->connect();

the you can use that $conn variable as a mysqli_query() parameter like

$result = mysqli_query($conn, $query);

this works for me.


I personally use mysqli_ext from Wolf Software with some minor modifications. Their website no longer has it available for download however I have placed a copy of my site for you to download. It is licensed under the GPL so you can tinker with it. It might replace your class, or it might give you the info you need to get your class working!


$sDB = new mysqli_ext($dbHost, $dbUser, $dbPass, $dbBase);
if ($sDB->connection_failed) {
    /* Error */

Select Query:

$sDB->select("SELECT * FROM `albums` WHERE `listedtype` = 'PUBLIC' ORDER BY `createdon` LIMIT ?, ?", "ii", $aStart, $aAlbums);

Other Queries:

$sDB->execute_query("UPDATE `photos` SET `views` = `views` + 1 WHERE `picid` = ?", "s", $sPhoto);

Download from: http://www.tip2tail.co.uk/files/mysqli.class.zip

Hope that helps!