Case个案的分配规约

Case个案的分配规则
trigger test on Case (after insert) {
 
List<Id> caseIds = new List<Id>{};

        for (Case theCase:trigger.new)
            caseIds.add(theCase.Id);
       
        List<Case> cases = new List<Case>{};
        for(Case c : [Select Id from Case where Id in :caseIds])
        {
            Database.DMLOptions dmo = new Database.DMLOptions();

            dmo.assignmentRuleHeader.useDefaultRule = true;
            c.setOptions(dmo);
           
            cases.add(c);
        }

        Database.upsert(cases);
}