how to connect to postgres database in php code example

Example: php connect to postgresql

<?php
    $db_connection = pg_connect("host=localhost dbname=dbname user=username password=password");
	$result = pg_query($db_connection, "SELECT lastname FROM employees");
?>
<?php  // with PDO
    $myPDO = new PDO('pgsql:host=localhost;dbname=dbname', 'username', 'password');
	$result = $myPDO->query("SELECT lastname FROM employees");
?>