I'm building a shopping cart and I would like to know how can I get the full category path for a product.

Let's say I have the following category structure: "Electronics (parent) -> TV -> Plasma TV" and my product belongs to the last category.

How should I write a script to return full category path like the one above.

My categories table looks like this:
- category_id
- category_parent_id
- category_name

Thank you.