<?php
//$em is the entity manager
$qb = $em->createQueryBuilder();
// Wasteful, will select all the properties (columns) for the entity
$qb
    ->select('Article')
    ->from('Entity\Article')
;
// Better, but won't provide a structure representing our object graph (returns a flat array)
$qb
    ->select('Article.title')
    ->from('Entity\Article')
;
// Best (although fragile if trying to manipulate/persist objects later)
$qb
    ->select('partial Article.{title}')
    ->from('Entity\Article')
;
// You can select multiple properties in the partial statement
$qb
    ->select('partial Article.{id,title,summary}')
    ->from('Entity\Article')
;