code: func (q *Query) IDs() ([]string, error) {
  	tx := q.pool.NewTransaction()
  	ids := []string{}
  	newTransactionQuery(q.query, tx).IDs(&ids)
  	if err := tx.Exec(); err != nil {
  		return nil, err
  	}
  	return ids, nil
  }
docs: // IDs returns only the ids of the models without actually retrieving the
  // models themselves. IDs will return the first error that occurred during the
  // lifetime of the query (if any).