Except as provided in Section 684.1 of this title, an action may be dismissed, without prejudice to a future action:
1. By the plaintiff, before the final submission of the case to the jury, or to the court, where the trial is by the court;
2. By the court, where the plaintiff fails to appear on the trial;
3. By the court, for the want of necessary parties;
4. By the court, on the application of some of the defendants, where there are others whom the plaintiff fails to prosecute with diligence;
5. By the court, for disobedience by the plaintiff of an order concerning the proceedings in the action; and 6. In all other cases, upon the trial of the action, the decision must be upon the merits.