Roll Up Contact Count on Account
trigger rollupCount on Child__c (after insert, after delete) { List masterList = new List(); Map masterMap = new Map(); for(List mstrList : [Select id, Trigger_Rollup_Count__c from Master__c]) { for(Master__c master : mstrList) { masterMap.put(master.Id, master); } } if(trigger.isInsert) { for(Child__c child : trigger.new) { if(masterMap.containskey(child.Master__c)){ if(masterMap.get(child.Master__c).Trigger_Rollup_Count__c != null){ Master__c mas = masterMap.get(child.Master__c); mas.Trigger_Rollup_Count__c = mas.Trigger_Rollup_Count__c + 1; masterList.add(mas); } else{ Master__c mas = masterMap.get(child.Master__c); mas.Trigger_Rollup_Count__c = 1; masterList.add(mas); } } } } if(trigger.isDelete) { for(Child__c child : trigger.Old) { if(masterMap.containskey(child.Master__c)) { Master__c mas = masterMap.get(child.Master__