Hi Saurav,You can utilize the below sample trigger model and change the field names and object name according to your code. The below trigger model based on Parent(Account) and Child(Contact).
Let me know if it helps.!trigger TotalTrigger on Contact (after insert, after update, after delete, after undelete) {
Set<Id> accountIds = new Set<Id>();
for(contact c: Trigger.isDelete? Trigger.old : Trigger.new){
if(c.AccountId != null)
{
accountIds.add(c.AccountId);
}
}
List<AggregateResult> summaryAggregateResult = [SELECT AccountId accId, Count(Id) sumAmt FROM Contact WHERE AccountId in:accountIds GROUP BY AccountId];
List<Account> accList = new List<Account>();
for(AggregateResult currentAggResult:summaryAggregateResult){
Account acc = new Account();
acc.Id = (Id)currentAggResult.get('accId');
acc.Total_Count__c = (Integer)currentAggResult.get('sumAmt');
accList.add(acc);
accountIds.remove((Id)currentAggResult.get('accId'));
}
for(Id currAccId : accountIds)
{
Account acc = new Account();
acc.Id = currAccId;
acc.Total_Count__c = null;
accList.add(acc);
}
update accList;
}
