iphone - 如何使用 Core Data 加快将新对象插入实体的速度

Question

这是我的代码，它获取一些 JSON 数据并将其插入核心数据室实体:

for (NSDictionary *room in rooms)
    {
        NSDictionary *thisroom = [room objectForKey:@"room"];
        NSString *roomidstring = [thisroom objectForKey:@"roomid"];
        int roomid = [roomidstring intValue];
        NSString *roomname = [thisroom objectForKey:@"roomname"];
        NSString *buildingidstring = [thisroom objectForKey:@"buildingid"];
        int buildingid = [buildingidstring intValue];

        // import into database
        NSManagedObject *roomInfo = [NSEntityDescription insertNewObjectForEntityForName:@"room" inManagedObjectContext:context];
        [roomInfo setValue:[NSNumber numberWithInteger:roomid] forKey:@"roomid"];
        [roomInfo setValue:roomname forKey:@"roomname"];
        [roomInfo setValue:[NSNumber numberWithInteger:buildingid] forKey:@"buildingid"];
         if (![context save:&error]) {
            NSLog(@"Whoops, couldn't save: %@", [error localizedDescription]);
        }
    }

插入大约 900 个对象时速度非常慢。有什么方法可以提高效率和/或加快速度吗？

谢谢!

Answer 1

是的，在完成循环之前不要保存，或者如果内存有问题，请分批保存。保存操作非常昂贵，因此您应该避免在像这样的紧密循环中经常保存。

for (NSDictionary *room in rooms)
{
    NSDictionary *thisroom = [room objectForKey:@"room"];
    NSString *roomidstring = [thisroom objectForKey:@"roomid"];
    int roomid = [roomidstring intValue];
    NSString *roomname = [thisroom objectForKey:@"roomname"];
    NSString *buildingidstring = [thisroom objectForKey:@"buildingid"];
    int buildingid = [buildingidstring intValue];

    // import into database
    NSManagedObject *roomInfo = [NSEntityDescription insertNewObjectForEntityForName:@"room" inManagedObjectContext:context];
    [roomInfo setValue:[NSNumber numberWithInteger:roomid] forKey:@"roomid"];
    [roomInfo setValue:roomname forKey:@"roomname"];
    [roomInfo setValue:[NSNumber numberWithInteger:buildingid] forKey:@"buildingid"];
}


if (![context save:&error]) {
     NSLog(@"Whoops, couldn't save: %@", [error localizedDescription]);
}