Doctrine 2 Index Inheritance

Question

i am new to Doctrine 2 am i trying to figure out how to do index inheritance with it.

What i am trying to achieve is to have a base class that defines some default columns along with necessary indexes for all entities within the application.

Example: All tables in my application will have created_on and modified_on, so i prepared one base @MappedSuperclass with those 2 columns in it.

Here is my code:

<?php

/**
 * @MappedSuperclass
 */
abstract class EntityAbstract
{
    /**
     * @Column(type="datetime", name="created_on", nullable=false)
     */
    protected $createdOn;

    /**
     * @Column(type="datetime", name="modified_on", nullable=true)
     */
    protected $modifiedOn;

}

/**
 * @Entity
 * @Table(name="member", indexes={@Index(name="credential", columns={"email_address", "password"})})
 */
class Member extends EntityAbstract
{
    /**
     * @Column(type="string", name="full_name", length=50)
     */
    protected $fullName;

    /**
     * @Column(type="string", name="email_address", length=50, unique=true, nullable=false)
     */
    protected $emailAddress;

    /**
     * @Column(type="string", name="password", length=40, nullable=false)
     */
    protected $password;       

}
?>

I want to enforce created_on to be an index, so i put @Index annotation in the base class for this particular column. Hoping that this will result in 2 indexes for Member which is created_on and email_address+password combination. This however results in indexes of the base class being overriden by the child class, thus created_on is not an index.

/**
 * @MappedSuperclass
 * @Table(indexes={@Index(name="timestampcreated", columns={"created_on"})})
 */
abstract class EntityAbstract

How do i achieve this in Doctrine 2? Have looked at single table inheritance, but my understanding is that it's meant for different purpose.

Answer 1

Here's a full solution for the way laid out at https://github.com/doctrine/orm/issues/5928#issuecomment-273624392, thanks to https://medium.com/@alexkunin/doctrine-symfony-adding-indexes-to-fields-defined-in-traits-a8e480af66b2

namespace App\EventListener;

use Doctrine\ORM\Event\LoadClassMetadataEventArgs;
use App\Entity\Member;

class MemberIndexListener
{
    public function loadClassMetadata(LoadClassMetadataEventArgs $eventArgs)
    {
        /** @var Doctrine\ORM\Mapping\ClassMetadata $classMetadata */
        $classMetadata = $eventArgs->getClassMetadata();
        if (Member::class === $classMetadata->getName())
        {
            $prefix = strtolower((new \ReflectionClass($classMetadata->getName()))->getShortName()); // you can omit this line and ...
            $classMetadata->table['indexes'][$prefix.'_created_on'] =  // ... replace `[$prefix.'_created_on']` with `[]` for automatic index naming
                ['columns' => ['username']
            ];
            // For UniqueConstraints, use:
            // $classMetadata->table['uniqueConstraints'][...] = ...
        }
    }
}

And in services.yaml:

services:
    App\EventListener\MemberIndexListener:
        tags:
            - { name: doctrine.event_listener, event: loadClassMetadata }