MySql Loop?

[Nick Thompson]

I have a scenario where I want to put php programming logic into the sql logic. Is this possible? Let me explain my scenario.

I have two tables, courses, and categories. Here's a dummed-down version of each:

Categories:
int id, int parent, string name

Courses:
int id, int parent, string name.

Now lets say in the categories table we have the following rows:

1   0   "English"
2   0   "Science"
3   2   "Chemistry"
4   2   "Physics"

Now Courses might have the following rows:

1   3   "chem101"
2   0   "english101"
3   4   "physics101"
4   2   "science101"

Lets say I wanted to get all the courses that are under the "science" category:

$resultset = mysql_query("select 'id' from categories where 'parent'=2");

foreach($resultset as $value){
   mysql_query("select * from courses where 'parent'=$value")
   //do something with the results
}
mysql_query("select * from courses where 'parent'=2")

I'm sure that there is a way to do this looping logic with one sql statement, but I can't figure out what that is. I did see something on "cursors" is that what would solve my problem?

Thanks,
Nick