RemoteEntity Example - Assumes the AppDelegate has a connection to the ManagedObjectContext.

RemoteEntity.h

//
//  RemoteEntity.h
//
//  Created by Christopher Bradford on 5/6/10.
//  Copyright 2010 INM United. All rights reserved.
//

@interface RemoteEntity :  NSManagedObject  
{

}

@property (nonatomic, retain) NSNumber * remote_update;
@property (nonatomic, retain) NSNumber * remote_id;

// Helper method for retrieving an instance of a remote entity given its id
+ (RemoteEntity *)entityWithRemoteID:(NSNumber *)remote_id;

// Helper method for retrieving the EntityDescription of the entity
+ (NSEntityDescription *)entityDescription;

@end

RemoteEntity.m

// 
//  RemoteEntity.m
//
//  Created by Christopher Bradford on 5/6/10.
//  Copyright 2010 INM United. All rights reserved.
//

#import "RemoteEntity.h"

@implementation RemoteEntity 

@dynamic remote_update;
@dynamic remote_id;

#pragma mark Core Data Helper Methods

+ (RemoteEntity *)entityWithRemoteID:(NSNumber *)remote_id
{
  NSFetchRequest *req = [[NSFetchRequest alloc] init];
  NSEntityDescription *entity = [NSEntityDescription entityForName:NSStringFromClass([self class]) inManagedObjectContext:APP_DELEGATE.managedObjectContext];
  
  [req setEntity:entity];
  [req setPredicate:[NSPredicate predicateWithFormat:@"remote_id = %@", remote_id]];
  
  NSError *error;
  NSArray *entities = [APP_DELEGATE.managedObjectContext executeFetchRequest:req error:&error];
  [req release];
  
  if ([entities count] != 0) {
    return [entities objectAtIndex:0];
  }
  
  return nil;
}

+ (NSEntityDescription *)entityDescription
{
  return [NSEntityDescription entityForName:NSStringFromClass([self class]) inManagedObjectContext:APP_DELEGATE.managedObjectContext];
}

@end