For each table I usually do something like this 

<?php
class people extends db {
  function load($id=-1) {
    $where = '';
    if($id!=-1) $where = "where id=".(int)$id;
    try {
      if(!self::$dbh) $this->connect();
      $result = self::$dbh->query("SELECT * FROM people $where");
      $rows = $result->fetchAll(PDO::FETCH_ASSOC); 
    } catch (PDOException $e) {
      $this->fatal_error($e->getMessage());
    }
    return $rows;
  }
?>