Is there a way to only return documents from a SharePoint Web Service Search?

Question

If a query the SharePoint Web Service Search, is there a way to send a parameter so that it only return documents?

There is of course the possibility to filter the result using the isDocument column, but is it possible during the query?

Answer 1

What do you mean by "during the query"? Providing a filter on the IsDocument column is applied query time! This is one way to return documents - another could be to create a search scope for documents only. But again, you will need to specify it in the query.

Answer 2

I guess you can use the beginsWith filhter in the query and query for all items that begins with a documente content type id:

<Where>
    <BeginsWith>
            <FieldRef Name='contentTypeId'/>
            <Value Type='Text'>0x0101</Value>
     </BeginsWith>
</Where>

see here for information about content type id and here is how you can use the query.