Question

I have a ‘Database.php’ that would handle database connections and would hand over mysql connections to classes that calls the Database class.

Database.php

<?php

class Database {

    private $domain = "localhost";
    private $usr = "root";
    private $pwd = "password";
    private $dbname = "testdb";
    private $db;

    function __contruct() {
    }

    function connect() {
        $this->db = mysqli_connect($domain, $usr, $pwd, $dbname);
        if ($db->connect_errno > 0) {
                die("DbConn Fail: \n ".$mysqli->connect_error);
        } else {
            return $this->db;
        }
    }
}

?>

I have the following test class trying to call the Database class to retrieve a connection and then use the connection in it’s SQl statements …

test.php

<?php
include('Database.php');
$db = new Database();
$conn = $db->connect();
$sql = "SELECT custid FROM `testdb`.`customer`";
$res = mysqli_query($conn, $sql);
$nrows = mysqli_num_rows($res);
echo "Num Rows Found: " . $nrows . "<br>";
if($res) {
echo "fetching...<br>";
    while ($row = mysqli_fetch_assoc($res)){
        echo "Found Customer ID: " . $row['custid'] . "<br>";
    }
}

?>

The problem I am facing is within the ‘Database.php’ class. Whenever a successful connection is established via the ‘connect()’ function, the Database class would return a valid mysql connection to the class calling the ‘Database’ class but from the demo below it is not working as intended.

May I know what I should do to fix the above problem ?

Answer 1

You should include the link and not the class initialization:

$res = mysqli_query($conn, $sql)

also your connection is wrong:

$this->db = mysqli_connect($this->domain, $this->usr, $this->pwd, $this->dbname);

also:

if ($this->db->connect_errno > 0) {