Problem with showing Unicode characters from Oracle database

[Célio Cidral Junior]

Hello all!

I am writing an application that connects to an Oracle 9i database using
OracleClient managed provider. There's a table with a field of NVARCHAR2
type, named TEXT, and another field of VARCHAR2 type, named COMMENT. The
application do insert text values into both fields correctly, even if high
code point Unicode characters are inserted into the TEXT field.
Unfortunately, those special characters are not returned correctly; instead,
the "¿" character is returned in place of them; only characters within ASCII
code range are returned as expected. I think there is some kind of
conversion from high Unicode code points to ASCII codes at the moment of
data return, somewhere in the OracleClient classes. In fact, I don't know
what's happening here. Following are the database parameters:

PARAMETER VALUE
------------------------------ ----------------------------------------
NLS_LANGUAGE AMERICAN
NLS_TERRITORY AMERICA
NLS_CURRENCY $
NLS_ISO_CURRENCY AMERICA
NLS_NUMERIC_CHARACTERS .,
NLS_CHARACTERSET WE8ISO8859P1
NLS_CALENDAR GREGORIAN
NLS_DATE_FORMAT DD-MON-RR
NLS_DATE_LANGUAGE AMERICAN
NLS_SORT BINARY
NLS_TIME_FORMAT HH.MI.SSXFF AM
NLS_TIMESTAMP_FORMAT DD-MON-RR HH.MI.SSXFF AM
NLS_TIME_TZ_FORMAT HH.MI.SSXFF AM TZR
NLS_TIMESTAMP_TZ_FORMAT DD-MON-RR HH.MI.SSXFF AM TZR
NLS_DUAL_CURRENCY $
NLS_COMP BINARY
NLS_LENGTH_SEMANTICS BYTE
NLS_NCHAR_CONV_EXCP FALSE
NLS_NCHAR_CHARACTERSET AL16UTF16
NLS_RDBMS_VERSION 9.2.0.3.0


And these are the session parameters:

PARAMETER VALUE
------------------------------ ----------------------------------------
NLS_LANGUAGE BRAZILIAN PORTUGUESE
NLS_TERRITORY BRAZIL
NLS_CURRENCY Cr$
NLS_ISO_CURRENCY BRAZIL
NLS_NUMERIC_CHARACTERS ,.
NLS_CALENDAR GREGORIAN
NLS_DATE_FORMAT DD/MM/RR
NLS_DATE_LANGUAGE BRAZILIAN PORTUGUESE
NLS_SORT WEST_EUROPEAN
NLS_TIME_FORMAT HH24:MI:SSXFF
NLS_TIMESTAMP_FORMAT DD/MM/RR HH24:MI:SSXFF
NLS_TIME_TZ_FORMAT HH24:MI:SSXFF TZR
NLS_TIMESTAMP_TZ_FORMAT DD/MM/RR HH24:MI:SSXFF TZR
NLS_DUAL_CURRENCY Cr$
NLS_COMP BINARY
NLS_LENGTH_SEMANTICS BYTE
NLS_NCHAR_CONV_EXCP FALSE

I also tried to change the NLS_LANG in the registry, as we can see
Microsoft's instructions in
http://support.microsoft.com/default.aspx?scid=kb;EN-US;Q322158, NLS_LANG
Settings section:

NLS_LANG changed from BRAZILIAN PORTUGUESE_BRAZIL.WE8MSWIN1252 to BRAZILIAN
PORTUGUESE_BRAZIL.AL16UTF16


But, when doing that, an exception is thrown when trying to connect to the
database:

System.Exception: Could not create an environment: OCIEnvCreate returned -1.
at System.Data.OracleClient.DBObjectPool.GetObject(Object owningObject,
Boolean& isInTransaction)
at
System.Data.OracleClient.OracleConnectionPoolManager.GetPooledConnection(Str
ing encryptedConnectionString, OracleConnectionString options,
OracleConnection owningObject, Boolean& isInTransaction)
at
System.Data.OracleClient.OracleConnection.OpenInternal(OracleConnectionStrin
g parsedConnectionString, Object transact)
at System.Data.OracleClient.OracleConnection.Open()
at Unicode.RecordSource.GetAll(DataTable table) in
C:\Testes\Unicode\RecordSource.vb:line 39
at Unicode.MainForm.LoadData() in C:\Testes\Unicode\MainForm.vb:line 179


In my connection, I included the UNICODE parameter:
DATA SOURCE=ORCL_TESTE;UNICODE=TRUE;UID=TESTE_UNICODE;PWD=TESTE_UNICODE

I tested with ODP.NET too and the problem persisted.

I searched the entire web for someone who had the same problem, but I
found no hope.

Can anyone take me out of this trouble?

Best regards,

Celio Cidral Jr
WEG Industries
Brazil