SQL Query: Search on childnode and property

[Bahl Christian]

Hi,

i´ve the following sql query:

SELECT * FROM nt:unstructured WHERE title='any title' AND 
articleDocument='false' AND /companyIds/collection-element IS NULL AND 
/menuIds/collection-element/menuId='1234'

Now my problem is this part " AND /companyIds/collection-element IS NULL AND 
/menuIds/collection-element IS NULL". It shows error in sql query language.
So my question: is it possible to do search properties on childnodes with sql 
query language? If so, can you please give me some examples?

Thx
Christian