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VSK98VSK98 

I have written the trigger , facing the error

Hi,

I am editing the record...............but trigger is firing in trigger.isafter && trigger.isupdate methods..............getting this below error 
Error:Apex trigger Opp1Trigger caused an unexpected exception, contact your administrator: Opp1Trigger: execution of AfterUpdate caused by: System.NullPointerException: Attempt to de-reference a null object: Class.opp1triggerhandler.UpdateTypeonopp: line 23, column 1
Information

Here is my method code
public static void UpdateTypeonopp(list<Opportunity1__c> lstopp1){
    
    system.debug('UpdateTypeonopp method calling');
    list<id> opprecords = new list<id>();
    for(Opportunity1__c opp1: lstopp1){
        if(opp1.Opportunity__c <>null && opp1.StageName__c == 'Qualification'){
        system.debug('UpdateTypeonopp method executedinloop');
    opprecords.add(opp1.Opportunity__c);
    }
    
    }
        
        for(Opportunity opp : [select id,Type from Opportunity where id = :opprecords]){
        opprec = new list<Opportunity>();
        opp.Type = 'New Customer';
        opprec.add(opp);
        }
        
        try{
        if(opprec.size()>0){
        update opprec;-------------------------getting error here
      }  
      }
      catch (dmlexception e){}
    }




 
Best Answer chosen by VSK98
Juan SpagnoliJuan Spagnoli

I think you are getting the error on: if(opprec.size()>0)

Where is opprec initialized? If the query in line 13 gives 0 result, the if statement will raise a null pointer.

Regards

All Answers

Juan SpagnoliJuan Spagnoli

I think you are getting the error on: if(opprec.size()>0)

Where is opprec initialized? If the query in line 13 gives 0 result, the if statement will raise a null pointer.

Regards

This was selected as the best answer
Juan SpagnoliJuan Spagnoli
Move opprec = new list<Opportunity>(); out of the for, je. That is your mistake. :)

Regards
Amit Chaudhary 8Amit Chaudhary 8
Please update your code like below
public static void UpdateTypeonopp(list<Opportunity1__c> lstopp1)
{
	system.debug('UpdateTypeonopp method calling');
	list<id> opprecords = new list<id>();
	for(Opportunity1__c opp1: lstopp1)
	{
		if(opp1.Opportunity__c <>null && opp1.StageName__c == 'Qualification')
		{
			system.debug('UpdateTypeonopp method executedinloop');
			opprecords.add(opp1.Opportunity__c);
		}
	}
		opprec = new list<Opportunity>();
		
		for(Opportunity opp : [select id,Type from Opportunity where id = :opprecords])
		{
			opp.Type = 'New Customer';
			opprec.add(opp);
		}
		
	try
	{
		if(opprec.size()>0)
		{
			update opprec;
		}  
	}
	catch (dmlexception e){}
}
http://amitsalesforce.blogspot.in/2015/06/trigger-best-practices-sample-trigger.html
Trigger Best Practices

1) One Trigger Per Object
A single Apex Trigger is all you need for one particular object. If you develop multiple Triggers for a single object, you have no way of controlling the order of execution if those Triggers can run in the same contexts

2) Logic-less Triggers
If you write methods in your Triggers, those can’t be exposed for test purposes. You also can’t expose logic to be re-used anywhere else in your org.

3) Context-Specific Handler Methods
Create context-specific handler methods in Trigger handlers

4) Bulkify your Code
Bulkifying Apex code refers to the concept of making sure the code properly handles more than one record at a time.

5) Avoid SOQL Queries or DML statements inside FOR Loops
An individual Apex request gets a maximum of 100 SOQL queries before exceeding that governor limit. So if this trigger is invoked by a batch of more than 100 Account records, the governor limit will throw a runtime exception

6) Using Collections, Streamlining Queries, and Efficient For Loops
It is important to use Apex Collections to efficiently query data and store the data in memory. A combination of using collections and streamlining SOQL queries can substantially help writing efficient Apex code and avoid governor limits

7) Querying Large Data Sets
The total number of records that can be returned by SOQL queries in a request is 50,000. If returning a large set of queries causes you to exceed your heap limit, then a SOQL query for loop must be used instead. It can process multiple batches of records through the use of internal calls to query and queryMore

8) Use @future Appropriately
It is critical to write your Apex code to efficiently handle bulk or many records at a time. This is also true for asynchronous Apex methods (those annotated with the @future keyword). The differences between synchronous and asynchronous Apex can be found

9) Avoid Hardcoding IDs
When deploying Apex code between sandbox and production environments, or installing Force.com AppExchange packages, it is essential to avoid hardcoding IDs in the Apex code. By doing so, if the record IDs change between environments, the logic can dynamically identify the proper data to operate against and not fail

Please ley us know if this will help you

Thanks
Amit Chaudhary