Ejemplo de uso de pgsql y pdo_pgsql

test.php

// Módulo pgsql:

<?php
  $c_pgsql = pg_connect("host=127.0.0.1 user=alu12345 password=12345 dbname=bd12345 port=1111");
  $r_pgsql = pg_query($c_pgsql, "select version()");
  $r = pg_fetch_assoc($r_pgsql);
  echo $r['version'];
?>

// Módulo pdo_pgsql:

<?php
  $c_pdo = new PDO("pgsql:host=127.0.0.1 user=alu12345 password=12345 dbname=bd12345 port=1111");
  $r_pdo = $c_pdo->query("select version()");
  $r = $r_pdo->fetch(PDO::FETCH_ASSOC);
  echo $r['version'];
?>