how connect to database postgres 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: php mysql connect pdo

$host = 'localhost'; // URL to the server
$user = 'root'; // Username (xampp = root)
$pw = ''; // Password (xampp = )
$dbname = 'database'; // The name of your database 
$dsn = "mysql:host=$host;dbname=$dbname";
$options = [PDO::MYSQL_ATTR_INIT_COMMAND => 'SET NAMES utf8']; // If you want to use utf-8 use this line

$db = new PDO($dsn, $user, $pw, $options); // Database Object
$db -> setAttribute(PDO::ATTR_DEFAULT_FETCH_MODE, PDO::FETCH_ASSOC); // Use this if you want an associate array
// $db -> setAttribute(PDO::ATTR_DEFAULT_FETCH_MODE, PDO::FETCH_ASSOC); Use this if you want an indexed array

$qry = 'select * from table;'; // Your query
$result = $db -> query($qry); // execute query

while ($row = $result -> fetch()) {
    $id = $row[/*column-name*/];
}