Count Activity History

Question

 Map<Id, Integer> mapActivityHistoryCountToCase = new Map<Id, Integer>();

           for( Case caseObj : [SELECT count(SELECT ID FROM ActivityHistories)  countActivity
                        FROM case where Id in : caseIds])
           {
               mapActivityHistoryCountToCase.put(caseObj.Id, caseObj.countActivity);
           }

I am not able to use Count for the activity history. please suggest .

I tried it this way too. But of no use.

  Map<Id, Integer> mapActivityHistoryCountToCase = new Map<Id, Integer>( 
                     [SELECT count(SELECT ID FROM ActivityHistories) 
                        FROM case where Id in : caseIds);

Answer 1

ActivityHistories is a list so it knows its own length already. Try this:

Map<Id, Integer> mapActivityHistoryCountToCase = new Map<Id, Integer>();

for( Case caseObj : [SELECT (SELECT Id FROM ActivityHistories) 
                     FROM Case WHERE Id IN :caseIds])
{
  mapActivityHistoryCountToCase.put(caseObj.Id, caseObj.ActivityHistories.size());
}