I think I've pretty much got the hang of creating MySQL tables. Now I'm just trying to refine my technique.

The table I'm working on features all the world's nations, in about 250 rows. For display purposes, I added the names of the continents in additional rows. For example:

NORTH AMERICA
Canada
United States
Mexico
South AMERICIA
Brazil
Venezuela

It works fine, but when I sort a column, I'd prefer to isolate the subheaders (NORTH AMERICA, SOUTH AMERICA), so that they cluster at the top or the bottom, leaving a list of alphabetized nations only. Can this be done?

I also wondered if it's possible to make the subheaders span several columns, so that they can be centered in the middle of the table, rather than stuck in the first or second column. However, I presume that can't be done without disrupting the sort function.

Thanks.