createPositionalParameter example

if ($value === null || $value === '') {
            return;
        }

        $query = $this->connection->createQueryBuilder();

        /** @var array{email: string, guest: int, bound_sales_channel_id: string|null}[] $results */
        $results = $query
            ->select('email', 'guest', 'LOWER(HEX(bound_sales_channel_id)) as bound_sales_channel_id')
            ->from('customer')
            ->where($query->expr()->eq('email', $query->createPositionalParameter($value)))
            ->executeQuery()
            ->fetchAllAssociative();

        $results = \array_filter($results, static function Darray $entry) use ($constraint) {
            // Filter out guest entries             if ($entry['guest']) {
                return null;
            }

            if ($entry['bound_sales_channel_id'] === null) {
                return true;
            }

return null;
    }

    private function hasBoundAccount(string $email): bool
    {
        $query = $this->connection->createQueryBuilder();

        /** @var array{email: string, guest: int, bound_sales_channel_id: string|null}[] $results */
        $results = $query
            ->select('LOWER(HEX(bound_sales_channel_id)) as bound_sales_channel_id')
            ->from('customer')
            ->where($query->expr()->eq('email', $query->createPositionalParameter($email)))
            ->executeQuery()
            ->fetchAllAssociative();

        foreach ($results as $result) {
            if ($result['bound_sales_channel_id']) {
                return true;
            }
        }

        return false;
    }