TaskRepository.php

<?php

class TaskRepository
{
    // __construct()
    
    public function getById(Id $id): TaskView
    {
         $sql = '
            SELECT
                t.id,
                t.name,
                t.project_id AS project,
                GROUP_CONCAT(sbt.name) AS subTasks,
                t.date
            FROM
                tasks t
            LEFT JOIN
                sub_tasks sbt
            WHERE
                id = :id
         ';
         
         $stmt = $this->connection->prepare($sql);
         $stmt->execute(['id' => $id->getValue()]);
         
         $stmt->setFetchMode(\PDO::FETCH_CLASS, TaskView::class);
         
         $task = $stmt->fetch();
         
         if (!$task) {
            throw new EntityNotFoundException();
         }
         
         return $task;
    }
}

TaskView.php

<?php

class TaskView
{
  private $id;
  private $name;
  private $project;
  
  /**
   * @var array
   */
  private $subTasks;
  
  /**
   * @var \DateTimeImmutable
   */
  private $date;
  
  public function getId(): string
  {
    return $this->id;
  }
  
  public function getName(): string
  {
    return $this->name;
  }
  
  public function getProjectId(): string
  {
    return $this->project;
  }
  
  public function getSubTasks(): array
  {
    return \explode(',', $this->subTasks);
  }
  
  public function getDate(): \DateTimeImmutable
  {
    return \DateTimeImmutable::createFromFormat('Y-m-d H:i:s', $this->date);
  }
}