Selecting Specific Fields

i think this work because you use mysql SGDB with ONLY_FULL_GROUP_BY mode deactivated, otherwise for others SGBG or when mysql ONLY_FULL_GROUP_BY is activated it will not work and you have to add a group by.
Generally all columns in the SELECT clause that do not have an aggregate need to be in the GROUP BY.

`
public function countNumberPrintedForCategory(Category $category)

{
    $conn = $this->getEntityManager()
        ->getConnection();

    $sql = '
        SELECT SUM(fc.numberPrinted) as fortunesPrinted, AVG(fc.numberPrinted) as fortunesAverage, cat.name
        FROM fortune_cookie fc
        INNER JOIN category cat ON cat.id = fc.category_id
        WHERE fc.category_id = :category
   GROUP BY cat.name
        ';
    $stmt = $conn->prepare($sql);
    $stmt->execute(array('category' => $category->getId()));

    return $stmt->fetch();

    return $this->createQueryBuilder('fc')
        ->andWhere('fc.category = :category')
        ->setParameter('category', $category)
        ->innerJoin('fc.category', 'cat')
        ->select('SUM(fc.numberPrinted) as fortunesPrinted, AVG(fc.numberPrinted) as fortunesAverage, cat.name')
		->groupBy('cat.name')
        ->getQuery()
        ->getOneOrNullResult();
}`

Hi,
great tutorial!
I have a question: I have an entity Story with an array collection field - photos (a story has many photos).
I'm trying to make a specific field select to get story info and all its photos

$db = $this->createQueryBuilder('s')
            ->andWhere('s.id = :id')
            ->setParameter('id', $no)
            ->select('s.id, s.title, s.abstract, s.photos');

gets me this error:
<blockquote>[Semantical Error] line 0, col 36 near 'photos FROM AppBundle\Entity\Story': Error: Invalid PathExpression. Must be a StateFieldPathExpression.</blockquote>
Do I need to make a join, or what is the solution here?
Thanks!

Great explanation. It would be interesting to know how to get an array of a attribute (id's) of selected objects, like in ids = 1,2,3,6.

Yo Matt!

Thanks for the nice comment! So, your behavior is "expected"... at least as far as this tutorial goes: we talk about how to hydrate objects and how to hydrate custom fields. What we don't do, is go so far as to hydrate an object *plus* some custom fields. And as far as I can tell (your situation makes great sense, but I've honestly never tried this approach) it's not well-supported. You have 2 options:

1) Use the ResultSetMapping - but then I think you need to make a raw SQL query, which is a bummer
2) Use a custom hydrator (https://techpunch.co.uk/dev...

The custom hydrator is probably the way to go :). There's a third option, which I *have* used... but doesn't quite apply here (it would require an extra key, probably per row, which is lame) - a listener on postLoad (I *have* used this in the past to add an extra property to a single object, every time you query for that object).

If you do go down any of these routes to set these values, just be careful not make sure you don't access these properties in other situations when you *haven't* actually queried for and populated them. I might even throw an exception in their getter methods if their values are null (meaning, they were never initialized).

Let me know how it goes!

I think this is a solid plan :). Custom hydrators are a bit more complex. And honestly, I've never (yet) run into a situation where I needed to create one in a real project.

Keep up the good work!

From the script (the video has it correctly)

"...I just said fortunesAverage with the as. The as
is optional - I didn't leave it out on purpose, but hey, good learning moment."

That first 'with' should be 'without'? Plus your query above actually *does* have the 'as' in it.