How to load an entity in Symfony without special fields

Question

i want to load an entity in my Controller, but dont want that the entity contains all fields. I did that before with the Jms-Serializer, where you can use the Groups Annotations, to avoid loading special fields. But i there you have to serialize your object to json/xml etc. And i dont want it serialized, i just want that groups function. I searched this site and the internet, but didnt found any solution for my problem.

Hope that someone understand what i mean and got an idea :)

Answer 1

There are a couple of possibilities:

1. Use partial objects (which will deliver objects where only specified attributes will be filled during hydration): http://docs.doctrine-project.org/projects/doctrine-orm/en/latest/reference/partial-objects.html#partial-objects

This is dangerous and you should be extra careful, because it looks like a fully loaded entity from all perspectives. You have to know why a field is null - just because it's null or because it simply hasn't been filled during hydration.

2. Don't hydrate objects but query for an array as hydration result (by that again you can specify which array keys you would like to get back): http://docs.doctrine-project.org/projects/doctrine-orm/en/latest/reference/dql-doctrine-query-language.html#array-hydration

Use this for performance-sensitive queries where you need a lot of read-only data and complex joins. But be aware that you don't have any entities you can manage with Doctrine (eg updating, deleting etc.).

3. Use DTO s which are objects but non-Doctrine-managed entities, there again you can specify what you would like to get hydrated with the NEW syntax: http://docs.doctrine-project.org/projects/doctrine-orm/en/latest/reference/dql-doctrine-query-language.html#new-operator-syntax

Basically the same advise as in 2) but this time you'll get objects. So you can use all your OOP wisdom.

4. Create your own custom hydration mode - there you can define on your own how entities should be hydrated: http://docs.doctrine-project.org/projects/doctrine-orm/en/latest/reference/dql-doctrine-query-language.html#custom-hydration-modes

Very advanced level. Only useful if you need a special hydration mode for several entities and really no other option delivers at performance and quality as you require it.

Answer 2

You can use partial objects, but you should be careful. For example:

$q = $em->createQuery("select partial u.{id,name,otherField} from MyApp\Entity\User u");

You can read more here: http://docs.doctrine-project.org/projects/doctrine-orm/en/latest/reference/partial-objects.html