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SAI CHARAN MADUGULASAI CHARAN MADUGULA 

Validation Rule to mandate the contact Role

Hello All,

Can anybody explain how to solve this?

1.I have to write a validation on the Contact with refrence to Account 
2.On the Contact there is a field called Role,it is a picklist value 
3.In that Picklist value i have to select XYZ Value and saved the contact on a account.
4.XYZ is the mandatory picklist value and user have to select this value.
5.If user tries to create a new contact again with a Role by selecting this xyzz picklist value. We have to fire the validation 

Requirement Question: 
Create a validation Rule To mandate a user not to create multiple contact on a single Account

Please help me out for this.


 
Roshni RahulRoshni Rahul
Hi Sai,

There is method by which user cannot create multiple contact on a single account.
Follow the steps below.

1. First create a number field in account with API name  Number_of_Contacts__c.
2. Create the following trigger in contact object
 
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, Number_of_Contacts__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.Number_of_Contacts__c = acct.Number_of_Contacts__c == null ? noOfConts : (acct.Number_of_Contacts__c + noOfConts);
        }
        
        update listAcct;    
    }
}

3. Now create validation rule in contact object

User-added image

4. If you try to add morethan one contact to an account, error will be thrown using validation.

Hope it helps for you.