Editing data in grid vs using an update script - sql

Question

I tried using Toad 12.1 DBA and SQLDeveloper to achieve my goal but i got same results.
When i update NVARCHAR2 cell in grid result, i can set and commit '€' sign as value. But when i execute an update script to do the same thing, it prints '?' character as data.
Here is the result when i edit and commit data in grid:
Here is the problem when i use update script to do the same thing:
I tried using differend NLS_LANG parameters but they did not work either.
AMERICAN_AMERICA.WE8ISO8859P9
AMERICAN_AMERICA.AL16UTF16
Database NLS parameters is here:
SELECT * FROM NLS_DATABASE_PARAMETERS where PARAMETER in ('NLS_CHARACTERSET','NLS_NCHAR_CHARACTERSET');
PARAMETER VALUE
------------ ------------
NLS_CHARACTERSET WE8ISO8859P9
NLS_NCHAR_CHARACTERSET AL16UTF16
Create script for the simple table:
CREATE TABLE AAA
(
NVARCHAR2COL NVARCHAR2(50)
);
I also tried using sqlplus to execute update script, but it printed question mark as data as well.
Edit: one more thing, using update script with unistr function works but i need to update data by using readable text:
UPDATE AAA SET NVARCHAR2COL = unistr('\20AC');
COMMIT;
Solution: using #Nationalized annotation on my JPA entities for NVARCHAR fields solved my problem.

Answer 1

Default data type of Text Literal is CHAR. CHAR strings can contain only ASCII symbols and there is no '€' symbol in ASCII table, so '€' is converted to '?' during statement compilation.
To use national character set string value must be prefixed with N. N function converts the data at compilation time to NCHAR.
UPDATE AAA SET NVARCHAR2COL = N'€'; should work.
Alternatively UPDATE AAA SET NVARCHAR2COL = to_nchar('€'); can be used.
When updating a value in a grid the development tool does the same transparently for the user.