Nls_database_parameters

Question

Hi All,
When I query with "SELECT * FROM nls_database_parameters" I get NLS_LANGUAGE as "AMERICAN" and NLS_TERRITORY as "AMERICA" .
Could you please tell me the steps to change thes as NLS_LANGUAGE = GERMAN and NLS_TERRITORY as "GERMANY" ?
Thanks !

Answer 1

Actually, the picture looks like this: NLS_DATABASE_PARAMETERS are used to evaluate CHECK constraints. They can be overridden only by specifying the parameters in SQL functions themselves.
Example:
Let assume that NLS_DATABASE_PARAMETERS shows NLS_LANGUAGE=AMERICAN and thus, usually, NLS_DATE_LANGUAGE=AMERICAN. Then:
create table TAB1 ( COL1 date, check (TO_CHAR(COL1,'MON') = 'DEZ') );
alter session set nls_language=GERMAN;
insert into TAB1 values (date '2011-12-01');The above code will fail because TO_CHAR will be evaluated with NLS_DATE_LANGUAGE=AMERICAN and the 1st of December will return DEC and not DEZ.
The below code will work:
create table TAB1 ( COL1 date, check (TO_CHAR(COL1,'MON','NLS_DATE_LANGUAGE=GERMAN') = 'DEZ') );
alter session set nls_language=GERMAN;
insert into TAB1 values (date '2011-12-01');Here, the third parameter to TO_CHAR overrides the NLS_DATABASE_PARAMETERS. You should usually use this third parameter to make your CHECK constraint independent of the database environment.
Neither NLS_SESSION_PARAMETERS nor NLS_INITIALIZATION_PARAMETERS influence the above example.
-- Sergiusz