[Zope] passing a parameter retrieved from a sql call

[Kate Legere]

I have a dtml-method that calls a bunch of sql inserts to update tables in a
relational database. The last thing I need to do is retrieve the
auto-increment ID from one table and use an update command to put it into a
joining table. I'm using MySQL 3.23.52 and it won't let me write the call as
:

UPDATE linksProjects
SET linksProjects.categoryId = categories.categoryId
(SELECT categories.categoryId
   FROM categories 
   WHERE categories.catTitle = <dtml-sqlvar catTitle type=string>) 

Apparently it won't let me reference two tables in a nested query at all. 

So if I just make a call to a select statement:

SELECT categories.categoryId
       FROM categories 
       WHERE categories.catTitle = <dtml-sqlvar catTitle type=string>

How do I pass the value retrieved back to a variable ... say 'ct' to use in 
The update statement? 

Kate