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_SORT but I'm wondering if there is another trick to do this in the query itself, without changing session variables

Solution 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.

Solution 2

(...) using JPA, how can I force a like query to be case insensitive and accent insensitive?

My answer will be JPQL oriented. For the former part, you could do:

where lower(name) like 'johny%';

For the later part, I'm not aware of a standard JPQL way to do it.

At the end, altering the session variables NLS_COMP and NLS_SORT is IMO the best option.

Comments

[AlfaTeK]

That doesn't solve the accent insensitive problem. SELECT NLS_UPPER ('áçgroe', 'NLS_SORT = XWEST_EUROPEAN_AI') "Uppercase" FROM DUAL; // returns ÁÇGROE which still has accents

[AlfaTeK]

This is not JPA compatible (no convert support) but it will work using hibernate/oracle so i'm accepting this answer... hope to not be unfair :)

[Martin Schapendonk]

I didn't look into all possible values of the NLS_SORT parameter. I guess there should be one that eliminates the accents. I'll see if I can add anything useful after my weekend.

[Ben George]

'Unfair' or wrong ? =) You asked for answer using JPA and accepted one that is not JPA compatible.