How to do a like case-insensitive and accent insensitive in Oracle 10gR2 and JPA?

Question

In a J2EE project, using JPA, how can I force a like query to be case insensitive and accent insensitive?

I know about changing session variables NLS_COMP and NLS_SO

Answer 1

Crudely, you can do something like

select  upper(convert('This is a têst','US7ASCII')),
        upper(convert('THIS is A test','US7ASCII'))
from dual;

select  1 from dual 
where upper(convert('This is a têst','US7ASCII')) =
             upper(convert('THIS is A test','US7ASCII'))

The CONVERT reduces the accented characters to the mapped ASCII equivalent, and the UPPER forces lower case to uppercase. The resultant strings should be matchable.