Query a SPList with managed metadata column with CAML including child terms

Question

I have a SharePoint list which has a managed metadata column. This is bound to my term store which look like as following:

• Cars
  • Mercedes
    • S600
    • CL65
    • G
  • BMW
    • 5
    • 6
    • 7
    • X5
  • Maybach
    • ...
  • Bentley

I want to query via CAML this list. I have a custom application page where the user is able to select the terms from the term store by drop downs. Given is a ListItem where the user has selected the term "S600" from the parent term "Mercedes". Lets think that the user now only selects "Mercedes".

How can I query the list with CAML so that I also get all items which where tagged with the children of the term "Mercedes"?

In short: How can I build a CAML query which can get all items with the selected parent terms child terms?

Answer 1

The magic words are TaxonomyField.GetWssIdsOfTerm.

This question is a dupicate of https://stackoverflow.com/questions/5258722/how-does-one-get-all-child-terms-of-a-sharepoint-term-in-c.