<?php
 require 'conexao.php'; //chama o arquivo de conexao

 $sql = 'SELECT country_id as "abrev",
                country_name as "Pais",
                region_id as regiao
         FROM hr.countries 
         WHERE region_id = 2';

 $rs = oci_parse($db,$sql); //oci_parse equivale ao mysqli_query()
 oci_execute($rs) 

 //oci_fetch_assoc() equivale ao mysqli_fetch_assoc()
 while($row = oci_fetch_assoc($rs)):
 echo "Região: " . $row['REGIAO'] . 
      ", País: " . $row['Pais'] . 
      ", abrv: " . $row['abrev'] . 
      "< /br>";
 endwhile;

?>