UpdateContactAddInfo

global class UpdateContactAddInfo implements Database.Batchable<sObject>
{
    global Database.QueryLocator start(Database.BatchableContext bc)
    {
        return Database.getQueryLocator(
           'SELECT ID, BillingStreet, BillingCity, BillingState, ' +
            'BillingPostalCode, (SELECT ID, MailingStreet, MailingCity, ' +
            'MailingState, MailingPostalCode FROM Contacts) FROM Account ' + 
            'Where BillingState = \'TX\''
             );
    }
    global void execute(Database.BatchableContext bc,List<Account> scope)
    {
        List<Contact> contacts=new List<Contact>();
        for(Account account:scope)
        {
            for(Contact contact:account.contacts)
            {
                contact.MailingStreet=account.BillingStreet;
                contact.MailingCity=account.BillingCity;
                contact.MailingState=account.BillingState;
                contact.MailingPostalCode=account.BillingPostalCode;
                contacts.add(contact);
   
            }
        }
        update contacts;
            
    }
    global void finish(Database.BatchableContext bc)
    {
        
    }
}