Creación de una Clase de Tipo de Formulario

Hey @TiCatoune,

Yeah, that's a classic issue with MySQL. There are 2 options you have:

1. For learning purposes in this tutorial we don't need that only_full_group_by, so you can just disable it in your MySQL config. Find your my.cnf and remove that ONLY_FULL_GROUP_BY from the sql_mode = "....." line. You will also need to restart MySQL for the change to take effect.

2. Rewrite the query. I think the easiest would be to replace StarshipRepository::findIncompleteOrderedByDroidCount() method with:

   public function findIncompleteOrderedByDroidCount(): Pagerfanta
    {
        $subQuery = $this->getEntityManager()
            ->createQueryBuilder()
            ->select('COUNT(sd.id)')
            ->from(StarshipDroid::class, 'sd')
            ->where('sd.starship = s.id')
            ->getDQL()
        ;
   
        $query = $this->createQueryBuilder('s')
            ->addSelect('(' . $subQuery . ') AS HIDDEN droidCount')
            ->andWhere('s.status != :status')
            ->orderBy('droidCount', 'ASC')
            ->setParameter('status', StarshipStatusEnum::COMPLETED)
            ->getQuery()
        ;
   
        return new Pagerfanta(new QueryAdapter($query));
    }
   

The subquery there should do the trick, but this query may cause performance issues. Though it's not important for learning purposes, so should be totally fine as well.

Let me know if you have any other problems with the project.

Cheers!

Hey @melkamar!

I agree with you 100%. Traditionally, the reason this hasn't been shown as a best practice because of all the extra code and concepts needed. For beginners, it can be overwhelming: an entity, DTO, form type, DTO <-> Entity transformer...

Luckily, there has been some improvements recently. symfony/object-mapper mostly removes the need for a custom transformer. There's also a proposal to add both validation and form mapping to a DTO.

Another thing that irks me about the current approach is the need for your entity properties always be nullable (even if they aren't so in the db).

My plan is to do a small, more advanced, micro-course on this specifically. Basically how to modify the code in this course to what you describe. Keep an eye out for that!

--Kevin

I forgot to mention the need for nullable properties - that was the biggest eyebrow raise when I started looking into this!

Thank you for the context around this topic, looking forward to the microcourse!