Ending position out of bounds: 10

Question

I am trying to get the first 10 characters from "Patient_Name__c" field into the "Patient_Id_Help__c" field but when i run the batch class it is throwing the error as "Ending position out of bounds: 10 ". Please find my batch class below

global class DataLoad implements Database.Batchable<sObject>{
             private String query;
             private Integer recordcount = 0;
             private boolean recurssion = true;

            global Database.QueryLocator start(Database.BatchableContext BC)
        {
            query='Select id,Patient_Name__c from ZS_Reports__c';
            return Database.getQueryLocator(query);
        }

        global void execute(Database.BatchableContext bc, List<ZS_Reports__c> scope) {
            recordCount=recordCount+scope.size();
            List<ZS_Reports__c> zs=new List<ZS_Reports__c>();

       for(ZS_Reports__c z:scope)
        {
            if(z.Patient_Name__c!=null)
            {
                z.Patient_Id_Help__c=z.Patient_Name__c.substring(0,10);
                   zs.add(z); 
            }
        }
                    system.debug('Updated Records:'+zs.size());
            if(zs.size()>0)
            {
                update zs; 
            }
        }
        global void finish(Database.BatchableContext bc) 
        {

        }
    } 

Can somebody help me to solve this issue.

Answer 1

Use left instead:

z.Patient_Id_Help__c=z.Patient_Name__c.left(10);

It does not throw an exception if there is less than 10 characters.

Remember to check for null first, if applicable:

if(z.Patient_Name__c != null) {
    z.Patient_Id_Help__c=z.Patient_Name__c.left(10);
}