  def self.get_comment_of(item_id, user_id)

    SqlHelper.validate_token([item_id, user_id])
    begin
      comment = Comment.where("(user_id=#{user_id}) and (item_id=#{item_id}) and (xtype='#{Comment::XTYPE_DIST_ACK}')").first
    rescue => evar
      Log.add_error(nil, evar)
    end

    return comment
  end
The software constructs all or part of an SQL command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended SQL command when it is sent to a downstream component.