Stored Procedure And Multiple Keys Which Could Be NULL

I have a table which has 10 columns which make up the secondary key. 1
or more of these columns can be set but the remaining columns in the
secondary key will be null. For example :


id k1 k2 k3 k4 k5 k6 k7 k8 k9 k10 data
-------------------------------------------------
0 1 1 - - - - - - - - test0
1 1 1 1 - - - - - - - test1
2 1 1 2 - - - - - - - test2
3 1 1 3 - - - - - - - test3
4 1 1 3 1 - - - - - - test4
5 1 2 1 - - - - - - - test5
6 1 2 2 - - - - - - - test6

Each row represents a node in a tree structure, the secondary key
columns point to which node in the tree. The above example has one
node in tree branch 1, three nodes in tree branch 1-1, one node in
branch 1-1-3 and two nodes in branch 1-2.

My question is how can I write a single stored procedure to return
only the nodes in a given tree branch without needing logic based on
looking for NULL parameters. I have written the stored procedure
below. If I want to retrieve all nodes in branch 1-1 (ie; test1, test2
and test3) then I want be able to call :

execute "mysp Test" 1, 1

But this only returns a single record, test0. The reason for this is
obvious if you look at the stored procedure. What I really need is way
of saying

execute "mysp Test" 1, 1, NOT NULL

so that it returns all records in branch 1-1 where Key3 is NOT NULL
but all subsequent keys are null, ie; Key4-Key10 are NULL. The stored
procedure must work with any number of secondary keys though, so I
could use it to call :

execute "mysp Test" 1, 1, 3, NOT NULL

which would retrieve test4.

Can anybody help me out here?

Thanks for reading.


Here's the stored procedure as it stands :

CREATE PROCEDURE [dbo].[mysp Test]
( @key1 smallint,
@key2 smallint=NULL,
@key3 smallint=NULL,
@key4 smallint=NULL,
@key5 smallint=NULL,
@key6 smallint=NULL,
@key7 smallint=NULL,
@key8 smallint=NULL,
@key9 smallint=NULL,
@key10 smallint=NULL ) AS

select * from TreePositionTest
where
key1=@key1 and
key2=@key2 and
key3=@key3 and
key4=@key4 and
key5=@key5 and
key6=@key6 and
key7=@key7 and
key8=@key8 and
key9=@key9 and
key10=@key10
GO