[Gambas-devel] Change to gb.db.odbc to use ODBC Connection Strings.

[zxMarce]

Benoît,

First off, with ODBC all .MoveXXX methods fail with "Result is forward only"
as expected, except .MoveFirst() and .MoveNext(). That is OK.

Second, I got the low level driver to return -1 as record count by
specifying different "TDS_Version" values in the connection string. For
example, "TDS_Version=7.2" returns zero, other versions return the expected
-1 (4.2, 7, 7.1, 7.3, etc). This is also OK, because it is
user-controllable.

But now that I have tested your mods, I must report the bad news: Both
.MoveNext and .Available properties always return FALSE, so there is no way
to cleanly exit a data retrieval loop.

I think the problem is in CResult.c at around line 145. That particular line
calls the driver's query_fill function but disregards the return value, so
the DB_ERROR, DB_OK and DB_NO_DATA return values are ignored.

If it helps, I cooked this mod in CResult.c, which made it work as expected
with ODBC, adjusting the return values of .MoveNext and .Available:

  //Next original line does not store the FILL call result, 
  //therefore any call will be assumed OK even when the 
  //ODBC driver says it failed.
  /*THIS->driver->Result.Fill(&THIS->conn->db,
                              THIS->handle,
                              pos,
                              THIS->buffer,
                              (pos > 0) && (pos ==
(DELETE_MAP_virtual_to_real(THIS->dmap, THIS->pos) + 1))
                             );*/

  //This next replacement line stores the FILL call result
  //in fillFailed so it can be checked later.
  int fillFailed = THIS->driver->Result.Fill(&THIS->conn->db,
                                         THIS->handle,
                                         pos,
                                         THIS->buffer,
                                         (pos > 0) && (pos ==
(DELETE_MAP_virtual_to_real(THIS->dmap, THIS->pos) + 1))
                                        );

  //Next, check whether the FILL above succeeded or failed and
  //return proper states in Result.MoveNext and Result.Available.
  if (fillFailed)
  {
    THIS->available = FALSE;
    return TRUE;
  }

Finally, if I misinterpreted your intentions (yet again), please disregard
my suggestions.

Regards,
zxMarce.



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