doctrine: QueryBuilder vs createQuery?

1. DQL is easier to read as it is very similar to SQL. If you don't need to change the query depending on a set of parameters this is probably the best choice.

2. Query Builder is an api to construct queries, so it's easier if you need to build a query dynamically like iterating over a set of parameters or filters. You don't need to do any string operations to build your query like join, split or whatever.

Query builder is just, lets say, interface to create query... It should be more comfortable to use, it does not have just add() method, but also methods like where(), andWhere(), from(), etc. But in the end, it just composes query like the one you use in the createQuery() method.

Example of more advanced use of query builder:

$em->createQueryBuilder()
            ->from('Project\Entities\Item', 'i')
            ->select("i, e")
            ->join("i.entity", 'e')
            ->where("i.lang = :lang AND e.album = :album")
            ->setParameter('lang', $lang)
            ->setParameter('album', $album);

They have different purposes:

• DQL is easier to use when you know your full query.
• Query builder is smarter when you have to build your query based on some conditions, loops etc.