program to update 2 database tables

Hi all

I have requirement where i need to update records in  2 database tables.

My first doubt is can we update 2 database tables at same time with code..

or if not..how do we do it one after another??

and suppose if i am doing database update 1 after another//

if first database table update is not happened, i want to stop the database update of second table???how can i achieve it?

and if first database table update is done successfully. 2nd dbtable also should get updated...

Thanks