Say, in AWS Dynamo, I have a table like this:

```
ID (HKey)   Date (RKey)   BoxName
0           1/1/2014      Box-1
1           2/1/2014      Box-1
2           3/1/2014      Box-2
3           4/1/2014      Box-3
4           5/1/2014      Box-3
5           5/1/2014      Box-1

```

I want to, in a single query, get the first row for each unique Box. There could be hundreds of boxes I need the first entry for at once, making individual requests inefficient.

I can't seem to find anything in the API that would allow me to do this. Is it possible? How would I do this?