database connection in php pdo code example

Example 1: php mysql pdo connection

<?php
$servername = "localhost";
$username = "username";
$password = "password";

try {
    $conn = new PDO("mysql:host=$servername;dbname=myDB", $username, $password);
    // set the PDO error mode to exception
    $conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
    echo "Connected successfully";
    }
catch(PDOException $e)
    {
    echo "Connection failed: " . $e->getMessage();
    }
?>

Example 2: database connection in php pdo

<?php
class database{
  private $host = "localhost";
  private $db_name = "php_basic";
  private $username = "root";
  private $password = "";
  private $conn;

  // connect database using PDO
  function connect_pdo(){
    try{
      $this->conn = new PDO("mysql:host=".$this->host.";dbname=".$this->db_name, $this->username, $this->password);
      return $this->conn;
    }
    catch(PDOException $ex){
      echo "Connection Error -->> ",$ex->getMessage();
      echo "<br>Error Code -->> ",$ex->getCode();
      echo "<br>Error occur in File -->> ",$ex->getFile();
      echo "<br>Error occur on Line no -->> ",$ex->getLine();

      $this->conn = null; // close connection in PDO
    }
  }
}
?>
  
//how to use 
<?php
include 'connect_db.php';
$database=new database();
$db = $database->connect_pdo();
?>

Example 3: pdo db connection

<?php
$pdo = new PDO('mysql:host=localhost;dbname=databasename', 'username', 'password');
?>

Example 4: connect php to mysql pdo

<?php 
  
	$pdo = new PDO('mysql:host=localhost;
  				dbname=the_name_of_your_databe,
  				'username', 
                'password'');
# by default your username is root 
# if you don't have a password don't fill in it

#(optional) : 
	$pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
	$pdo->setAttribute(PDO::ATTR_DEFAULT_FETCH_MODE, PDO::FETCH_OBJ);

?>