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How to read Unicode data in Oracle?

regzero
regzero asked
on
Medium Priority
578 Views
Last Modified: 2013-11-20
Hi,

Does anyone know how to read Unicode data in Oracle database and write onto a text file? Because when I read it, some Unicode charaters change to "¿".

My code is:

void CMyDlg::ReadUnicode()
{
   _RecordsetPtr recordset = NULL;
   _CommandPtr command = NULL;
    _variant_t vRowsAffected;
    _variant_t vNull;
    vNull.vt = VT_ERROR;
    vNull.scode = DISP_E_PARAMNOTFOUND;
    HRESULT hr;
    hr = recordset.CreateInstance(__uuidof(Recordset));
    hr = command.CreateInstance(__uuidof(Command));

    command->ActiveConnection = GetConnection();
    command->CommandType      = adCmdText;
    command->CommandText      = "SELECT TEXT FROM UNICODE WHERE ID=1";

    recordset = command->Execute(&vRowsAffected, &vNull, adCmdText);

    if (recordset!=NULL)
    {
      recordset->MoveFirst();
      while (!recordset->adoEOF)
      {
             _variant_t vcode = recordset->Fields->GetItem(L"TEXT")->GetValue();
          recordset->MoveNext();
      }
    }
    recordset->Close();
    command->Release();
}

I have a string "đăng" stored in Oracle database and it displays in memory when I view it: "00142BBC  BF 00 BF 00 6E 00 67  ¿.¿.n.g".

Please help,
Thanks
Comment
Watch Question

Commented:
Hi!
It seems like you put no UNICODE string into the database - Your data looks like you make it by
WCHAR* wch = L"uung";
where 'u' char is the locale specific char (not ASCII 127).
Can you fisrtly put proper unicode string into the base and test?
To make unicode string use MultiByteToWideChar API

Author

Commented:
I insert value from web using JSP. I set request.setCharacterEncoding("UTF-8").

For unicode characters with 0x00XX, e.g: "ê"->0x00EA, value is OK.
Ex, I have a string like this "lê lá là" in DB, and on the memory it shows:
001422E4  6C 00 EA 00 20 00 6C  l.ê. .l
001422EB  00 E1 00 20 00 6C 00  .á. .l.
001422F2  E0 00 00 00 00 00 02  à......

but with unicode value like 0xXXXX, e.g: "ạ"->0x1EA1, it's wrong. It converts value to "¿" ->0x00BF.

Author

Commented:
:) It's OK now, I solved it

Commented:
Hi!
Can you place here your solution ???? just for learning?

Author

Commented:
Hi Migel,
I didn't know you posted.

I found the document in Oracle page, it's all here:

http://otn.oracle.com/products/oracle8i/htdocs/OTN_ODBC_Unicode_cabaird.htm

Dang
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