public function findIdentifiersByTag($tag) { $this->connect(); $statementHandle = $this->databaseHandle->prepare('SELECT "identifier" FROM "tags" WHERE "context"=? AND "cache"=? AND "tag"=?'); $statementHandle->execute([md5($this->environmentConfiguration->getApplicationIdentifier()), $this->cacheIdentifier, $tag]); return $statementHandle->fetchAll(\PDO::FETCH_COLUMN); }