Start with a channel aggregate.

app/src/Domain/Aggregate/ChannelAggregate.php

@@ -0,0 +1,49 @@
+<?php
+
+namespace Slovocast\Domain\Aggregate;
+
+use Slovocast\Domain\Entity\Episode;
+use Slovocast\Domain\Entity\Channel;
+
+class ChannelAggregate 
+{
+    /**
+     * @param Channel $channel
+     * @param array<Episode> $episodes
+     */
+    public function __construct(
+        protected Channel $channel,
+        protected array $episodes
+    ) { 
+        $this->setEpisodes($episodes);
+    }
+
+    public function hasEpisodes(): bool
+    {
+        return (bool) count($this->episodes);
+    }
+
+    /**
+     * @return array<Episode>
+     */
+    public function getEpisodes(): array
+    {
+        return $this->episodes;
+    }
+
+    public function addEpisode(Episode $episode): void
+    {
+        $this->episodes[] = $episode;
+    }
+
+    /**
+     * @param array<Episode> $episodes
+     * @return void
+     */
+    public function setEpisodes(array $episodes): void
+    {
+        foreach ($episodes as $episode) {
+            $this->addEpisode($episode);
+        }
+    }
+}

app/src/Domain/Repository/Channel/ChannelAggregateRepository.php

@@ -0,0 +1,40 @@
+<?php
+
+namespace Slovocast\Domain\Repository\Channel;
+
+use Slovocast\Domain\Entity\Episode;
+use Slovocast\Domain\Aggregate\ChannelAggregate;
+use Slovocast\Domain\Repository\Channel\ChannelRepositoryInterface;
+use Slovocast\Domain\Repository\Episode\EpisodeRepositoryInterface;
+use Slovocast\Infrastructure\Api\Database\DatabaseHandlerInterface;
+
+class ChannelAggregateRepository
+{
+    public function __construct(
+        protected DatabaseHandlerInterface $database,
+        protected ChannelRepositoryInterface $channelRepository,
+        protected EpisodeRepositoryInterface $episodeRepository,
+    ) { }
+
+    public function getChannelWithEpisodes(int $id): ChannelAggregate
+    {
+        $channel = $this->channelRepository->get($id);
+        $episodes = $this->episodeRepository->getFromChannel($channel);
+        return new ChannelAggregate($channel, $episodes);
+    }
+
+    public function getChannelByEpisode(Episode $episode): ChannelAggregate
+    {
+        $query = "SELECT c.id as channel_id, e.id as episode_id
+            FROM channel c
+            LEFT JOIN episodes e ON e.channel_id = c.id
+            WHERE e.id = :id";
+
+        $results = $this->database->query($query, [
+            ":id" => $episode->getId()
+        ]);
+
+        $row = array_shift($results);
+        return $this->getChannelByEpisode($row['id']);
+    }
+}

app/src/Domain/Repository/Episode/EpisodeRepository.php

@@ -17,7 +17,8 @@ class EpisodeRepository implements EpisodeRepositoryInterface
     ) { }
 
     /**
-     * @param array The query results from the database
+     * @param array $results The query results from the database
+     * @return Episode
      */
     protected function getEpisodeFromResults(array $results): Episode
     {