ODBC API SQLBindParameter Bug When Passing Chinese Characters?

Question

Hi Everyone,
I am accessing Oracle 10g database (on Windows XP) from Windows XP machine.
Table TEST_TABLE is defined as
CREATE TABLE TEST_TABLE(NVARCHAR2(255))
Using ODBC (code comes shortly) data are successfully inserted into table using SQLBindParameter to bind parameter values.
The same data can be succesfully read from the table. But the query to retrieve only those rows containing chinese characters simply doesn't work.
I am using SQLBindParameter to bind a parameter placeholder when executing SELECT * FROM TEST_TABLE WHERE C1=?. It simply doesn't find the rows if parameter value contains chinese characters, it only finds rows if parameter contains pure ASCII data.
Am I missing something here? NVARCHAR2 data type should be able to always store unicode data. My database settings are:
NLS_NCHAR_CHARACTERSET=AL16UTF16 and NLS_CHARACTERSET=WE8MSWIN1252
Here is the code:
#include "stdafx.h"
#include <windows.h>
#include <sql.h>
#include <sqlext.h>
#define SQLCheck(x)          if (SQL_SUCCESS != x) {\
                                                            SQLINTEGER native;\
                                                            SQLSMALLINT msgLength;\
                                                            SQLCHAR szState[SQL_MAX_MESSAGE_LENGTH],szErrorMessage[SQL_MAX_MESSAGE_LENGTH];\
                                                            ::SQLError(henvAllConnections,hdbc,hstmt,szState,&native,szErrorMessage,SQL_MAX_MESSAGE_LENGTH,&msgLength);\
                                                            printf("Error state=%s, native=%d, message = %s\n",szState,native,szErrorMessage);\
                                                            DebugBreak();\
#define MAX_CONNECT_LEN 512
int tmain(int argc, TCHAR* argv[])
     SQLRETURN nRetCode     ;     
     HENV henvAllConnections;
     HDBC hdbc(0);
     HSTMT hstmt(SQL_NULL_HSTMT);
     //TEST_TABLE is created using the following query CREATE TABLE TEST_TABLE(C1 NVARCHAR2(255))
     nRetCode = ::SQLAllocEnv(&henvAllConnections);
     SQLCheck(nRetCode)
     nRetCode = ::SQLAllocConnect(henvAllConnections, &hdbc);
     SQLCheck(nRetCode)
     HWND hWnd = ::GetDesktopWindow();
     TCHAR szConnectOutput[MAX_CONNECT_LEN];
     TCHAR *pszConnectInput = const_cast<LPTSTR>(_T("DSN=o10 american;UID=no;PWD=no#"));
     SWORD nResult;
     nRetCode = ::SQLDriverConnect(hdbc, hWnd, reinterpret_cast<SQLTCHAR *>(pszConnectInput),
          SQL_NTS, reinterpret_cast<SQLTCHAR *>(szConnectOutput), sizeof(szConnectOutput),
          &nResult, SQL_DRIVER_NOPROMPT);
     SQLCheck(nRetCode)
     nRetCode = ::SQLAllocStmt(hdbc, &hstmt);
     SQLCheck(nRetCode)
     TCHAR* szQuery = T("INSERT INTO TESTTABLE(C1) VALUES(?)");
     nRetCode = ::SQLPrepare(hstmt,reinterpret_cast<UCHAR*>(szQuery), SQL_NTS);     
     SQLCheck(nRetCode)
     SQLSMALLINT     DataType,DecimalDigits,Nullable;
     SQLUINTEGER     ParamSize;
     nRetCode = ::SQLDescribeParam(hstmt, 1, &DataType, &ParamSize,&DecimalDigits, &Nullable);
     SQLCheck(nRetCode)
     wchar_t chineseData[6];
     chineseData[0]=0x0023;chineseData[1]=0x0050;chineseData[2]=0x0043;chineseData[3]=0xBA85;chineseData[4]=0xc870;chineseData[5]=0x0000;
     wchar_t asciiData[] = L"test data";
     SQLLEN sqlnts = SQL_NTS;
     nRetCode = ::SQLBindParameter(hstmt, (UWORD)1,SQL_PARAM_INPUT,SQL_C_WCHAR,SQL_WVARCHAR,ParamSize,DecimalDigits,chineseData,static_cast<SQLINTEGER>(wcslen(chineseData) * sizeof(wchar_t)),&sqlnts);
     SQLCheck(nRetCode)
     nRetCode = ::SQLExecute(hstmt);
     SQLCheck(nRetCode)
     nRetCode = ::SQLBindParameter(hstmt, (UWORD)1,SQL_PARAM_INPUT,SQL_C_WCHAR,SQL_WVARCHAR,ParamSize,DecimalDigits,asciiData,static_cast<SQLINTEGER>(wcslen(asciiData) * sizeof(wchar_t)),&sqlnts);
     SQLCheck(nRetCode)
     nRetCode = ::SQLExecute(hstmt);
     SQLCheck(nRetCode)
     nRetCode = SQLFreeStmt(hstmt,SQL_DROP);
     SQLCheck(nRetCode)
     TCHAR* pszSQL = _T("SELECT * FROM TEST_TABLE WHERE C1=?");
     int nMaxLength = 1024;
     SQLLEN lLength = SQL_NTS,dataLen;
     TCHAR lpszFieldName[256];
     SWORD nActualLen,nSQLType,nScale,nNullability;
     SQLULEN     nPrecision;
     SQLSMALLINT nResultCols;
     wchar_t pWData[1024];
     nRetCode = ::SQLAllocStmt(hdbc, &hstmt);
     SQLCheck(nRetCode)
     SQLLEN paramLength = static_cast<SQLINTEGER>(wcslen(chineseData) * sizeof(wchar_t));     
     nRetCode = ::SQLBindParameter(hstmt,1,SQL_PARAM_INPUT,SQL_C_WCHAR,SQL_WVARCHAR,nMaxLength,0,chineseData,paramLength,&sqlnts);     
     SQLCheck(nRetCode)
     nRetCode = ::SQLExecDirect(hstmt, reinterpret_cast<SQLTCHAR *>(pszSQL), SQL_NTS);
     SQLCheck(nRetCode)
     nRetCode = ::SQLNumResultCols(hstmt, &nResultCols);
     SQLCheck(nRetCode)
     nRetCode = ::SQLDescribeCol(hstmt, 1,     reinterpret_cast<SQLTCHAR *>(lpszFieldName), 255, &nActualLen,&nSQLType,&nPrecision,&nScale,&nNullability);          
     SQLCheck(nRetCode)
     nRetCode = ::SQLBindCol(hstmt, 1,     SQL_C_WCHAR, pWData, (nPrecision+1) * sizeof(wchar_t),     &dataLen);
     SQLCheck(nRetCode)
     nRetCode = nRetCode = ::SQLFetch(hstmt);
     if (SQL_NO_DATA_FOUND == nRetCode)
          printf("No data found although data are in the table!\n");
     else
          printf("Found chinese data in the table!\n");
     //now try with another qay of SQLBindParameter, which uses length instead of SQL_NTS     
     nRetCode = ::SQLBindParameter(hstmt,1,SQL_PARAM_INPUT,SQL_C_WCHAR,SQL_WVARCHAR,nMaxLength,0,chineseData,paramLength,&paramLength);
     SQLCheck(nRetCode)
     nRetCode = ::SQLExecDirect(hstmt, reinterpret_cast<SQLTCHAR *>(pszSQL), SQL_NTS);
     SQLCheck(nRetCode)
     nRetCode = nRetCode = ::SQLFetch(hstmt);
     if (SQL_NO_DATA_FOUND == nRetCode)
          printf("No chinese data found even using different way of SQLBindParameter, although chinese data are in the table!\n");
     else
          printf("Found chinese data in the table!\n");
     //now try with ascii data
     nRetCode = ::SQLBindParameter(hstmt,1,SQL_PARAM_INPUT,SQL_C_WCHAR,SQL_WVARCHAR,nMaxLength,0,asciiData,static_cast<SQLINTEGER>(wcslen(asciiData) * sizeof(wchar_t)),&sqlnts);
     SQLCheck(nRetCode)
     nRetCode = ::SQLExecDirect(hstmt, reinterpret_cast<SQLTCHAR *>(pszSQL), SQL_NTS);
     SQLCheck(nRetCode)
     nRetCode = ::SQLBindCol(hstmt, 1,     SQL_C_WCHAR, pWData, (nPrecision+1) * sizeof(wchar_t),     &dataLen);
     SQLCheck(nRetCode)
     nRetCode = ::SQLFetch(hstmt);
     if (SQL_NO_DATA_FOUND == nRetCode)
          printf("also didn't found ascii data!\n");
     else
          printf("found ascii data!\n");
     nRetCode = ::SQLFreeStmt(hstmt,SQL_DROP);
     SQLCheck(nRetCode)
     nRetCode = SQLAllocStmt(hdbc,&hstmt);
     SQLCheck(nRetCode)
     //now read all values to prove data are really there
     TCHAR* pszSQLAllDaya = _T("SELECT * FROM TEST_TABLE");
     nRetCode = ::SQLExecDirect(hstmt, reinterpret_cast<SQLTCHAR *>(pszSQLAllDaya), SQL_NTS);
     SQLCheck(nRetCode)
     nRetCode = ::SQLBindCol(hstmt, 1,     SQL_C_WCHAR, pWData, (nPrecision+1) * sizeof(wchar_t),     &dataLen);
     SQLCheck(nRetCode)
     while (SQL_NO_DATA_FOUND != SQLFetch(hstmt))
          printf("data from table %S\n",pWData);
     nRetCode =      ::SQLFreeStmt(hstmt, SQL_DROP);
     SQLCheck(nRetCode)
hstmt = SQL_NULL_HSTMT;
     ::SQLDisconnect(hdbc);
     ::SQLFreeConnect(hdbc);
     ::SQLFreeEnv(henvAllConnections);
     return 0;
Regards,
Darko

Answer 1

Hi Darko,
You are right, I think you have discovered a bug in the 10.1.0.2 ODBC driver. I believe this problem is described in Bug 3249731.
The good news is that this is already fixed in the 10.1.0.3 ODBC driver. Do you have access to MetaLink? Goto patches and download "Patchset 3842783" which is the ORACLE ODBC INSTANT CLIENT DRIVER PATCH VERSION 10.1.0.3.0
Good Luck
Nat