+ Start a Discussion
Admin PartAdmin Part 

create a field no. of location on account object (data type in number). write a trigger that will create as much no. of contact object as value in no. of locations when account object is cretaed.

trigger locationAcc on Account(before insert)
{
List<Account> listAcc= new List<Account>();
List<Contact> listCon= new List<Contact>();
for(Account a: trigger.new)
{
listAcc.add(a.Location__c);
for(Contact c: listAcc )
{
// please give any idea.
}
}
Best Answer chosen by Admin Part
Varun SinghVarun Singh
HI Admin part Try this code
 
trigger ContactCount on Contact (after insert, after update, after delete, after undelete) {
    Map<Id, List<Contact>> mapAcctIdContactList = new Map<Id, List<Contact>>();
    Map<Id, List<Contact>> mapAcctIdDelContactList = new Map<Id, List<Contact>>();
    Set<Id> AcctIds = new Set<Id>();    
    List<Account> listAcct = new List<Account>();
    
    if(trigger.isInsert) {
        for(Contact Con : trigger.New) {
            if(String.isNotBlank(Con.AccountId)) {
                if(!mapAcctIdContactList.containsKey(Con.AccountId)) {
                    mapAcctIdContactList.put(Con.AccountId, new List<Contact>());
                }
                mapAcctIdContactList.get(Con.AccountId).add(Con); 
                AcctIds.add(Con.AccountId);
            }   
        }  
    }
    
    if(trigger.isUpdate) {
        for(Contact Con : trigger.New) {
            if(String.isNotBlank(Con.AccountId) && Con.AccountId != trigger.oldMap.get(Con.Id).AccountId) {
                if(!mapAcctIdContactList.containsKey(Con.AccountId)){
                    mapAcctIdContactList.put(Con.AccountId, new List<Contact>());
                }
                mapAcctIdContactList.get(Con.AccountId).add(Con); 
                AcctIds.add(Con.AccountId);
            } else if(String.isBlank(Con.AccountId) && String.isNotBlank(trigger.oldMap.get(Con.Id).AccountId)) {
                if(!mapAcctIdDelContactList.containsKey(Con.AccountId)){
                    mapAcctIdDelContactList.put(Con.AccountId, new List<Contact>());
                }
                mapAcctIdDelContactList.get(Con.AccountId).add(Con);   
                AcctIds.add(trigger.oldMap.get(Con.Id).AccountId);
            }
        }  
    }
    
    if(trigger.isUndelete) {
        for(Contact Con : trigger.new) {
            if(String.isNotBlank(Con.AccountId)){
                if(!mapAcctIdContactList.containsKey(Con.AccountId)){
                    mapAcctIdContactList.put(Con.AccountId, new List<Contact>());
                }
                mapAcctIdContactList.get(Con.AccountId).add(Con);     
                AcctIds.add(Con.AccountId);
            }
        }  
    }      

    if(trigger.isDelete) {
        for(Contact Con : trigger.Old) {
            if(String.isNotBlank(Con.AccountId)){
                if(!mapAcctIdDelContactList.containsKey(Con.AccountId)){
                    mapAcctIdDelContactList.put(Con.AccountId, new List<Contact>());
                }
                mapAcctIdDelContactList.get(Con.AccountId).add(Con);    
                AcctIds.add(Con.AccountId); 
            }
        }  
    }   
    
    if(AcctIds.size() > 0) {
        listAcct = [SELECT Id, NumberofLocations__c FROM Account WHERE Id IN : AcctIds];
        
        for(Account acct : listAcct) {
            Integer noOfConts = 0;
            if(mapAcctIdContactList.containsKey(acct.Id)) {
                noOfConts += mapAcctIdContactList.get(acct.Id).size();
            }
            if(mapAcctIdDelContactList.containsKey(acct.Id)) {
                noOfConts -= mapAcctIdDelContactList.get(acct.Id).size();
            }
            acct.NumberofLocations__c  = acct.NumberofLocations__c  == null ? noOfConts : (acct.NumberofLocations__c    + noOfConts);
        }
        
        update listAcct;    
    }
}

I hope its work well for you,please select my answer as best

Thanlks,
Varun​