I need to operate on a big table with lots of records, but only on rows where the primary key starts with a number. Because obviously its a good idea to differentiate types of records in this way …. only joking! Its just one of those little tasks that crops up from time to time.
The Fast and Dirty Way
select code from products where substr(code,1,1) in (0,1,2,3,4,5,6,7,8,9)
Oracle Regular Expression Method
select code from products where regexp_like(code,'^[[:digit:]]')