global Database.QueryLocator start(Database.BatchableContext BC){
   //String query = 'Select Id FROM Call_Plan_Scenario__c LIMIT 2';
   String fieldsreturned;
   str=Utilities.GetHeaders(db_ObjectName)+'rn';
   string[] fields=Utilities.GetQuery(db_ObjectName );
   String query = 'select '+ String.join(fields, ',') +' from '+ db_ObjectName;
   return database.getQueryLocator(query);
}

global void execute(Database.BatchableContext BC, List<sobject> scope){
           for(sObject rec : scope){
                 str+=Utilities.GetRecord(rec,db_ObjectName);
                 system.debug('**str**'+str);
                 //str+='|'+'n';
            }
}

global void finish(Database.BatchableContext BC){
    system.debug('**str**'+str);
            string nameOfFile = db_ObjectName;
            nameOfFile = nameOfFile.substring(0,nameOfFile.length()-3);
            system.debug(nameOfFile);

            Transient Attachment myAttachment = new Attachment();
            myAttachment.Body = Blob.valueOf(str);
            myAttachment.Name = nameOfFile +'.txt';
            myAttachment.ParentId = callPlanScenario.Id;
            myAttachment.ContentType = 'text/csv';

            insert myAttachment;
    AsyncApexJob a = [SELECT Id, Status, NumberOfErrors, JobItemsProcessed, TotalJobItems, CreatedBy.Email FROM AsyncApexJob WHERE Id =:BC.getJobId()];
    if(a.NumberOfErrors ==0){
       // Database.executeBatch(new DeleteRecordsBatch(callPlanScenario,db_ObjectName,counter),1500);
    }
 }