主题：sql使用出错，用foxtable链接成功，而预览出错

 HENV   hEnv = NULL; // Env Handle from SQLAllocEnv()
 HDBC   hDBC = NULL; // Connection handle

 RETCODE retcode;

 // Allocate memory for ODBC Environment handle
 SQLAllocEnv (&hEnv);

 // Allocate memory for the connection handle
 SQLAllocConnect (hEnv, &hDBC);

 // Connect to the data source "test" using userid and password.
 SQLCHAR szConnect[] = "DRIVER={SQL Server};SERVER=192.168.0.1;UID=sa;PWD=Goncely;DATABASE=testdb";
 SQLCHAR szOutConn[1024];
 SQLSMALLINT n(0);
 retcode = SQLDriverConnect(hDBC, m_hWnd, szConnect, strlen((char*)szConnect),
     szOutConn, 1024, &n, SQL_DRIVER_NOPROMPT);
 if (retcode == SQL_SUCCESS || SQL_SUCCESS_WITH_INFO)
 {
  TRACE("connect to sql server success ");

  HSTMT  hStmt = NULL;// Statement handle

  // Allocate memory for the statement handle
  retcode = SQLAllocStmt (hDBC, &hStmt);
  
  UCHAR  szSqlStr[128]= "SELECT * from student" ;

  // Prepare the SQL statement by assigning it to the statement handle
  retcode = SQLPrepare (hStmt, szSqlStr, sizeof (szSqlStr));

  // Execute the SQL statement handle
  retcode = SQLExecute (hStmt);

  SQLSMALLINT ColumnCount(0);
  retcode = SQLNumResultCols(hStmt, &ColumnCount);
  TRACE("total %d cols in db. ", ColumnCount);

  char name[11];
  int age;
  SQLINTEGER StrLen_or_Ind;
  retcode = SQLBindCol(hStmt, 1, SQL_C_CHAR, name, 24, &StrLen_or_Ind);
  retcode = SQLBindCol(hStmt, 2, SQL_C_SLONG, &age, 0, &StrLen_or_Ind);

  do
  {
   retcode = SQLFetch(hStmt);
   TRACE("name: %s, age: %d. ", name, age);
  }
  while(retcode == SQL_SUCCESS);

  // Free the allocated statement handle
  SQLFreeStmt (hStmt, SQL_DROP);

  // Disconnect from datasource
  SQLDisconnect(hDBC);
 }
 else if(/*retcode == SQL_SUCCESS_WITH_INFO ||*/ retcode == SQL_ERROR)
 {
  TRACE("ai ");
  SQLCHAR Sqlstate[6], MessageText[1024];
  SQLINTEGER NativeError;
  SQLSMALLINT TextLength;
  SQLGetDiagRec(SQL_HANDLE_DBC, hDBC, 1, Sqlstate, &NativeError,
   MessageText, 1024, &TextLength);
  TRACE("%s ", MessageText);
 }
 else
 {
  TRACE("failed for others ");
 }

 // Free the allocated connection handle
 SQLFreeConnect(hDBC);

 // Free the allocated ODBC environment handle
 SQLFreeEnv(hEnv);

这是vc源代码，据说能直接连接远程SQL，有谁能破解并用到狐表吗？