Get record count in Azure DocumentDb

[Clippy]

Get record count in Azure DocumentDb

[Clippy]

Until the implementation of the "count" keyword, you should do your query in a store procedure on the server. Take care to not get all columns/properties in your query if you want only a count.

Select only the id like;

```
dc.CreateDocumentQuery(update.SelfLink, "SELECT c.id FROM c")

```