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heinleinandy Simple error on a simple trigger
Hi,
I have spent a year in college on C++, and understand computer programming fairly well.
With that said, this is my first attempt and apex, triggers and SOQL (or SQL for that matter) and i could use some help.
Here is my apex class
public class calculateResources {
public static void addResource(PersonalProject__c PP){
MonthlyProject__c MP = [SELECT Hours_This_Term__c, WholeProject__c FROM MonthlyProject__c WHERE id= : PP.MonthlyProject__c];
MP.Hours_This_Term__c += PP.hours_spent__c;
WholeProject__c WP = [SELECT AllocatedHours__c FROM WholeProject__c WHERE id= :MP.WholeProject__c];
WP.AllocatedHours__c += PP.hours_spent__c;
}
public static void addResource(PersonalProject__c PP){
MonthlyProject__c MP = [SELECT Hours_This_Term__c, WholeProject__c FROM MonthlyProject__c WHERE id= : PP.MonthlyProject__c];
MP.Hours_This_Term__c += PP.hours_spent__c;
WholeProject__c WP = [SELECT AllocatedHours__c FROM WholeProject__c WHERE id= :MP.WholeProject__c];
WP.AllocatedHours__c += PP.hours_spent__c;
}
}
and here is my trigger
trigger addResource on PersonalProject__c (after insert) {
for (Integer i = 0; i < Trigger.new.size(); i++)
calculateResources.addResource(Trigger.new[i]);
}
When I create a personal project, i need MonthlyProject__c.hours_this_term__c to update by adding personalProject__c.hours_spent__c. and similarly with whole project updating from MP.hours this term.
When i run this, i get
Apex trigger addResource caused an unexpected exception, contact your administrator: addResource: execution of AfterInsert caused by: System.NullPointerException: Attempt to de-reference a null object: Class.calculateResources.addResource: line 5, column 9
Any help would be great, i am not real sure where the null pointer is that im attempting to dereference
Thanks
Message Edited by heinleinandy on 07-07-2008 07:04 AM
Message Edited by heinleinandy on 07-07-2008 07:05 AM
To fix it, either do an explicit test for null (if MP==null) or use a try block. You probably just want to ignore the PP's that are missing all the fields, so you could just log the error and then leave the routine.
try {
MonthlyProject__c MP = [SELECT Hours_This_Term__c,
WholeProject__c FROM MonthlyProject__c WHERE id= :PP.MonthlyProject__c];
MP.Hours_This_Term__c += PP.hours_spent__c;
// etc.
} catch (NullPointerException e) {
System.debug('That null pointer thing happened again on ' + PP.id);
}