title: How to query multiple items in DynamoDB (iOS)?
body: <p>I would like to get the items of many videoIds, not like in this code only one video Item? Is there a way to query multiple items from an index?</p>
  
  <pre><code>AWSDynamoDBObjectMapper *objectMapper = [AWSDynamoDBObjectMapper defaultDynamoDBObjectMapper];
  AWSDynamoDBQueryExpression *queryExpression = [AWSDynamoDBQueryExpression new];
  
  queryExpression.indexName = @"getVideoItem";
  queryExpression.keyConditionExpression = @"#id = :id";
  queryExpression.expressionAttributeNames = @{
                                               @"#id" : @"id",
                                               };
  queryExpression.expressionAttributeValues = @{
                                                @":id" : videoId,
                                                };
  __weak typeof(self) weakSelf = self;
  
  [objectMapper query:[PublicVideos class]
           expression:queryExpression
    completionHandler:^(AWSDynamoDBPaginatedOutput * _Nullable response, NSError * _Nullable error) {
        if (!error) {
            dispatch_async(dispatch_get_main_queue(), ^{
                if ([weakSelf.delegate respondsToSelector:@selector(ServerConnectionHandlerVideoListRecevied:)]) {
                    [weakSelf.delegate ServerConnectionHandlerVideoListRecevied:response.items];
                }
            });
        }
    }];
  </code></pre>