Clean URLs questions

[Mutley]

I have a list of categories, that are like:

<a href="list.php?cat=2">Ice Cream</a>

 

I figure, that refering to an ID column, is more efficent and suitable than using the category name (for queries). So if I did a mod_rewrite, it would look like:

 

mydomain.com/categories/2

 

However, what I would like it to do is:

 

mydomain.com/categories/Ice_Cream

 

Now I figured that I can't do this because I would lose the ID reference? Any soloution to this? And how would I auto include a underscore to replace spaces?

 

Thanks in advance,

Nick.

 

 

[Helmet]

Use <a href="list.php?cat=ice_cream">Ice Cream</a>

 

and build a php function to get the category id from the cat value