How to Connect Database in PHP Using OOPS

How to set up a database connection, using Object-Oriented Programming (OOP), PHP and MySQL. Below following step:

Step 1: To create files DatabaseClass.php and write a class with a function( query_executed,get_rows,get_fetch_data ).

class DatabaseClass
{
    private $host = "localhost"; // your host name
    private $username = "root"; // your user name
    private $password = ""; // your password
    private $db = "test_db"; // your database name
    public
    function __construct()
    {
        mysql_connect($this - > host, $this - > username, $this - > password) or die(mysql_error("database"));
        mysql_select_db($this - > db) or die(mysql_error("database"));
    }
    // this method used to execute mysql query
    protected
    function query_executed($sql)
    {
        $c = mysql_query($sql);
        return $c;
    }
    public
    function get_rows($fields, $id = NULL, $tablename = NULL)
    {
        $cn = !emptyempty($id) ? " WHERE $id " : " ";
        $fields = !emptyempty($fields) ? $fields : " * ";
        $sql = "SELECT $fields FROM $tablename $cn";
        $results = $this - > query_executed($sql);
        $rows = $this - > get_fetch_data($results);
        return $rows;
    }
    protected
    function get_fetch_data($r)
    {
        $array = array();
        while ($rows = mysql_fetch_assoc($r))
        {
            $array[] = $rows;
        }
        return $array;
    }
}

Step 2: Create index.php file,

<?php
include("DatabaseClass.php");
$obj = new DatabaseClass ();
$a = $obj-> get_rows (implode(",",array("ID","post_date","post_title")), '' , "tablenane") ; // there are pass two parameters one is table fields and second is table name
echo "<pre>";
print_r($a);
echo "</pre>";
?>

 

Output: