mannharleen

public class AccountProcessor {
    
    @future
    public static void countContacts(List<Id> accountId_lst) {
        
        Map<Id,Integer> account_cno = new Map<Id,Integer>(); 
        List<account> account_lst_all = new List<account>([select id, (select id from contacts) from account]);
        for(account a:account_lst_all) {
            account_cno.put(a.id,a.contacts.size()); //populate the map