Help !!! - Search using english base alphabet for French diacritic/accent

Question

Hello -
I am searching using wild card in Oracle 9i database, as follows -
select * from test
where Upper(name) like 'A%'.
It returns all the names upper and lower beginning with 'A'.
We do have french data and few of the names begin with Á,Ä and à.
In order to fetch all of the rows based on the base letter ,ignoring diacritic in the above same query,
I have tried couple of settings as follows before executing the query -
ALTER SESSION SET NLS_SORT='FRENCH';
Or
ALTER SESSION SET NLS_COMP=ANSI;
ALTER SESSION SET NLS_SORT=GENERIC_BASELETTER;
It didnot work. After reading the documentation, I have tried the query, for equality (=) search with some test data and seems to be working...
So my guess is these settings are only useful if you have same exact name(data) for french as well english. Wildcard search '%' 'like' cases donot work.
It would be really great if someone knows work-around for the query I have mentioned -
select * from test
where Upper(name) like 'A%'.
to do get all the rows based on generic base letter ignoring those accents/diacritic.
Or is there any other way we can implement this.
I need to implement the generic solution for all english alphabets search in our application.
ANY HELP would be REALLY APPRECIATED....
Thank you so much....
Rama...

Answer 1

Hi Rama,
For all current versions of the Oracle database, NLS_COMP=ANSI affects the following SQL operators only:
WHERE =,WHERE >,WHERE <, START WITH, IN/OUT, BETWEEN, CASE WHEN, HAVING, ORDER BY.
All other operators, such as LIKE, perform comparisons in binary mode only. They do not honor the NLS_SORT value. I hope that explains why you are seeing the behaviour that you described.
This will be enhanced in 10gR2, where all SQL functions and operators will be able to honor the NLS_SORT value.
You may be able to use the workaround below, if all your LIKE operations place the '%' at the end.
e.g.
ALTER SESSION SET NLS_SORT=GENERIC_BASELETTER;
SELECT * FROM test
WHERE NLSSORT (name,1,1) = NLSSORT('A');
name
Älex
andrew
Ace
àlan
Good luck!
Nat