oracle text search contains

Hi helpers,

i have a table with part numbers and part descriptions.

The partno. looks like KD-005657

When i want to search for this i use

select * from parts where contains(partno,'KD-')>0

But there is no result.

Only using contains(partno,'KD%') creates a result.

I tried these also: KD\-, KD& found in documentation to text query.

How could i find results when seraching all partno with KD- ?

Thanks for you response.

Frank