code: func (r *GormWorkItemRepository) FindFirstItem(ctx context.Context, spaceID uuid.UUID, id uuid.UUID) (*float64, error) {
  	res := WorkItemStorage{}
  	tx := r.db.Model(WorkItemStorage{}).Where("id=? and space_id=?", id, spaceID).First(&res)
  	if tx.RecordNotFound() {
  		return nil, errors.NewNotFoundError("work item", id.String())
  	}
  	if tx.Error != nil {
  		return nil, errors.NewInternalError(ctx, tx.Error)
  	}
  	return &res.ExecutionOrder, nil
  }
docs: // FindFirstItem returns the order of the target workitem