PHP函数和数据库连接

Question

I'm trying to keep one file for PHP connection instead of using mysqli_connect on every page.

I have a config.ini file which has the Db credentials, this file i call in a php file db_connect.php The code of db_connect.php is below:

//stores hostname or the server name
$hostName;
//username for the database
$userName;
//password for the database
$password;
//database name
$dbName;

$ini = parse_ini_file('../../config/config.ini');   
while(list($key,$value) = each($ini))
{
    if($key == 'hostName')
    {
        $hostName = $value; //retrieving value of host name.
    }
    else if($key == 'userName')
    {
        $userName = $value; //retrieving database user name
    }
    else if($key == 'password')
    {
        $password = $value; //retrieving database password
    }
    else if($key == 'dbName')
    {
        $dbName = $value;   //retrieving database name.
    }
}
$connectobject1 = new mysqli($hostName, $userName, $password, $dbName);
if ($connectobject1->connect_errno) 
{
    echo "Connection Failed";
    exit();
}

using the above code, i'm able to create a connection to the database. Now when i include db_connect.php in my index.php file, i use require_once 'db_connect.php' however the problem starts when in index.php my functions execute. These functions are not able to access the connection string. a sample of my index.php code is below:

//Creating DB connection
require_once '../connect/db_connect.php';

//Checking DB connection
if(!$connectobject1) 
{
    //connection to DB failed
    header('Location: /pages/error/error.php?id=0'); 
    exit();
}

function checkuser($UserID, $connectobject1)
{

    //function code
}

I've read that it is not a good practice to use global for connections.

How can I proceed with my connections?

Answer 1

use a file like this..

config.php file which will have server details

 <?php

    // PHP Database Constants
    // Database Constants
        defined('DB_SERVER') ? null : define("DB_SERVER", "127.0.0.1");
        defined('DB_PORT') ? null : define("DB_PORT", "8889");
        defined('DB_USER')   ? null : define("DB_USER", "popat234");
        defined('DB_PASS')   ? null : define("DB_PASS", "4JfQuuQnzU6yfPdm");
        defined('DB_NAME')   ? null : define("DB_NAME", "demo");

    ?>

database.php which will have the connection settings

<?php

require_once ('config.php');

class MYSQLDatabase {

    private $connection;

  function __construct() {
    $this->open_connection();
  }

  public function open_connection() {
    $this->connection = mysqli_connect(DB_SERVER, DB_USER, DB_PASS, DB_NAME, DB_PORT);
    if(mysqli_connect_errno()) {
      die("Database connection failed: " . 
           mysqli_connect_error() . 
           " (" . mysqli_connect_errno() . ")"
      );
    }
  }