diff --git a/lib/Db/AssignmentMapper.php b/lib/Db/AssignmentMapper.php
index d7d3a1eb8..816276ace 100644
--- a/lib/Db/AssignmentMapper.php
+++ b/lib/Db/AssignmentMapper.php
@@ -60,7 +60,19 @@ class AssignmentMapper extends QBMapper implements IPermissionMapper {
 		$qb = $this->db->getQueryBuilder();
 		$qb->select('*')
 			->from('deck_assigned_users')
-			->where($qb->expr()->eq('card_id', $qb->createNamedParameter($cardId, PDO::PARAM_INT)));
+			->where($qb->expr()->eq('card_id', $qb->createNamedParameter($cardId, IQueryBuilder::PARAM_INT)));
+		$users = $this->findEntities($qb);
+		foreach ($users as $user) {
+			$this->mapParticipant($user);
+		}
+		return $users;
+	}
+
+	public function findIn(array $cardIds): array {
+		$qb = $this->db->getQueryBuilder();
+		$qb->select('*')
+			->from('deck_assigned_users')
+			->where($qb->expr()->in('card_id', $qb->createNamedParameter($cardIds, IQueryBuilder::PARAM_INT_ARRAY)));
 		$users = $this->findEntities($qb);
 		foreach ($users as $user) {
 			$this->mapParticipant($user);
diff --git a/lib/Db/LabelMapper.php b/lib/Db/LabelMapper.php
index 7f6de33bf..aeccef539 100644
--- a/lib/Db/LabelMapper.php
+++ b/lib/Db/LabelMapper.php
@@ -79,6 +79,19 @@ class LabelMapper extends DeckMapper implements IPermissionMapper {
 		return $this->findEntities($qb);
 	}
 
+	public function findAssignedLabelsForCards($cardIds, $limit = null, $offset = null): array {
+		$qb = $this->db->getQueryBuilder();
+		$qb->select('l.*', 'card_id')
+			->from($this->getTableName(), 'l')
+			->innerJoin('l', 'deck_assigned_labels', 'al', 'l.id = al.label_id')
+			->where($qb->expr()->in('card_id', $qb->createNamedParameter($cardIds, IQueryBuilder::PARAM_INT_ARRAY)))
+			->orderBy('l.id')
+			->setMaxResults($limit)
+			->setFirstResult($offset);
+
+		return $this->findEntities($qb);
+	}
+
 	/**
 	 * @param numeric $boardId
 	 * @param int|null $limit