Problem with a migration sql error General error: 1215

Question

I'm using Symfony 4 and I try to do a migration with the command :

php bin/console doctrine:migrations:migrate

But error pop up :

SQLSTATE[HY000]: General error: 1215 Can not add external index constraints

I have already tried a lot of things with the code but it's still not working

<?php

declare(strict_types=1);

namespace DoctrineMigrations;

use Doctrine\DBAL\Schema\Schema;
use Doctrine\Migrations\AbstractMigration;

/**
 * Auto-generated Migration: Please modify to your needs!
 */
final class Version20191018125033 extends AbstractMigration
{
    public function getDescription() : string
    {
        return '';
    }

    public function up(Schema $schema) : void
    {
        // this up() migration is auto-generated, please modify it to your needs
        $this->abortIf($this->connection->getDatabasePlatform()->getName() !== 'mysql', 'Migration can only be executed safely on \'mysql\'.');

        $this->addSql('CREATE TABLE article (id INT AUTO_INCREMENT NOT NULL, category_id INT NOT NULL, title VARCHAR(255) NOT NULL, content LONGTEXT NOT NULL, image VARCHAR(255) NOT NULL, created_at DATETIME NOT NULL, INDEX IDX_23A0E6612469DE2 (category_id), PRIMARY KEY(id)) DEFAULT CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci ENGINE = InnoDB');
        $this->addSql('CREATE TABLE category (id INT AUTO_INCREMENT NOT NULL, title VARCHAR(255) NOT NULL, description VARCHAR(255) NOT NULL, PRIMARY KEY(id)) DEFAULT CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci ENGINE = InnoDB');
        $this->addSql('CREATE TABLE comment (id INT AUTO_INCREMENT NOT NULL, article_id INT NOT NULL, author VARCHAR(255) NOT NULL, content LONGTEXT NOT NULL, createtd_at DATETIME NOT NULL, INDEX IDX_9474526C7294869C (article_id), PRIMARY KEY(id)) DEFAULT CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci ENGINE = InnoDB');
        $this->addSql('ALTER TABLE article ADD CONSTRAINT FK_23A0E6612469DE2 FOREIGN KEY (category_id) REFERENCES category (id)');
        $this->addSql('ALTER TABLE comment ADD CONSTRAINT FK_9474526C7294869C FOREIGN KEY (article_id) REFERENCES article (id)');
    }

    public function down(Schema $schema) : void
    {
        // this down() migration is auto-generated, please modify it to your needs
        $this->abortIf($this->connection->getDatabasePlatform()->getName() !== 'mysql', 'Migration can only be executed safely on \'mysql\'.');

        $this->addSql('ALTER TABLE comment DROP FOREIGN KEY FK_9474526C7294869C');
        $this->addSql('ALTER TABLE article DROP FOREIGN KEY FK_23A0E6612469DE2');
        $this->addSql('DROP TABLE article');
        $this->addSql('DROP TABLE category');
        $this->addSql('DROP TABLE comment');
    }
}