FreeTDS Development Group

["Thompson, Bill D (London)" <bill_d_thompson AT ml.com>]

Hey James,

Well I've solved the issue that I was getting with bcp_sendrow() /
bcp_batch()  / bcp_done() 

Hopefully this will be the cause of your woes as well.

If not, at least I've proved there's nothing generically wrong with this
functionality.

Here's the patch. It's not what I expected at all... :-)

bcp_batch(DBPROCESS * dbproc)
{
    TDSSOCKET *tds = dbproc->tds_socket;
    int rows_copied = 0;

    if (dbproc->bcp.direction == 0) {
        _bcp_err_handler(dbproc, SYBEBCPI);
        return -1;
    }

    tds_flush_packet(tds);

+    tds->state = TDS_QUERYING;

    if (tds_process_simple_query(tds) != TDS_SUCCEED)
        return FAIL;
    rows_copied = tds->rows_affected;

    _bcp_start_new_batch(dbproc);


    return (rows_copied);
}

/* end the transfer of data from program variables */

DBINT
bcp_done(DBPROCESS * dbproc)
{
    TDSSOCKET *tds = dbproc->tds_socket;
    int rows_copied = -1;

    if (dbproc->bcp.direction == 0) {
        _bcp_err_handler(dbproc, SYBEBCPI);
        return -1;
    }
    tds_flush_packet(tds);

+    tds->state = TDS_QUERYING;

    if (tds_process_simple_query(tds) != TDS_SUCCEED)
        return FAIL;
    rows_copied = tds->rows_affected;

    _bcp_clear_storage(dbproc);

    return (rows_copied);



HTH,

Bill




> -----Original Message-----
> From: Thompson, Bill D (London) 
> Sent: 18 December 2003 10:10
> To:   'FreeTDS Development Group'
> Subject:      RE: [freetds] Status: bcp
> 
> Houston, 
> 
> we DO have a problem, but I can reproduce here.
> I'm working on it....
> 
> Bill
> 
> > -----Original Message-----
> > From:       Thompson, Bill D (London) 
> > Sent:       18 December 2003 09:32
> > To: 'FreeTDS Development Group'
> > Subject:    RE: [freetds] Status: bcp
> > 
> > James,
> > 
> > STOP! STOP!
> > 
> > let me run some tests on bcp_sendrow() and see if there's a generic
> > problem.
> > 
> > your understanding is not complete.
> > 
> > bcp_exec and bcp_sendrow work essentially the same way, with one
> > difference.
> > bcp_exec reads data from a file, whereas bcp_sendrow gets the data from
> > your
> > bcp_bind()-ed host variables.
> > Thereafter they should use the same code.
> > 
> > the "insert bulk" statement is sent in both cases, - It's key to the bcp
> > conversation on SQL server.
> > It (and the metadata token that follows it) are sent when a new bcp
> > operation is started or after bcp_batch() is called to "commit" a buch
> of
> > previously sent data.
> > 
> > see this code in bcp_sendrow():
> > 
> > 
> >     /* The first time sendrow is called after bcp_init,  */
> >     /* there is a certain amount of initialisation to be */
> >     /* done...                                           */
> > 
> >     if (!(dbproc->sendrow_init)) {
> > 
> >         /* first call the start_copy function, which will */
> >         /* retrieve details of the database table columns */
> > 
> >         if (_bcp_start_copy_in(dbproc) == FAIL)
> >             return (FAIL);
> > 
> >         /* set packet type to send bulk data */
> >         tds->out_flag = 0x07;
> > 
> >         if (IS_TDS7_PLUS(tds)) {
> >             _bcp_send_colmetadata(dbproc);
> >         }
> > 
> >         dbproc->sendrow_init = 1;
> > 
> >     }
> > 
> > 
> > bcp_batch() says "I'm done" , sends the packet, and then starts a new
> > "transaction" (a new INSERT BULK statement and metadata).
> > 
> > 
> > There is a problem with tds7_put_bcpcol(), which is called to construct
> > the
> > wire data for each column. here's the code:
> > 
> >     if (bcpcol->data_size == 0) {
> >         if (!bcpcol->db_nullable) {
> >             /* too bad if the column is not nullable */
> >             return TDS_FAIL;
> >         } 
> > 
> > and here's how tds7_put_bcpcol is called from bcp_sendrow:
> > 
> >     if (_bcp_get_prog_data(dbproc) == SUCCEED) {
> > 
> >         if (IS_TDS7_PLUS(tds)) {
> >             tds_put_byte(tds, row_token);   /* 0xd1 */
> > 
> >             for (i = 0; i < dbproc->bcp.db_colcount; i++) {
> > 
> >                 /* send the data for each column */
> >                 ret = tds7_put_bcpcol(tds, dbproc->bcp.db_columns[i]);
> > 
> >                 if (ret == TDS_FAIL) {
> >                     _bcp_err_handler(dbproc, SYBEBCNN);
> >                 }
> > 
> >             }
> >             return SUCCEED;
> > 
> > If the error condition is hit in tds7_put_bcpcol a BAD ROW will be
> > constructed (the bad column having neen nissed out....)
> > 
> > 
> > 
> > HTH,
> > 
> > 
> > Bill
> > 
> >   
> > 
> > > -----Original Message-----
> > > From:     James K. Lowden [SMTP:jklowden AT schemamania.org]
> > > Sent:     18 December 2003 05:22
> > > To:       TDS Development Group
> > > Subject:  [freetds] Status: bcp
> > > 
> > > I haven't been able to bcp from host variables using current FreeTDS.
> > In
> > > comparing my home-grown application to freebcp, it became clear why
> > > freebcp works and mine doesn't.  Or, at least, it became clear how
> > they're
> > > different.  
> > > 
> > > freebcp relies on bcp_exec(), which in turn is written directly to
> > libtds.
> > >  
> > > 
> > > My application uses bcp_bind() and bcp_sendrow().  Apparently,
> > > bcp_sendrow() causes the "insert bulk" statement (or the row metadata;
> > the
> > > dump is at the office) to be sent.  This is not what the server
> expects,
> > > and the session is quickly terminated.  
> > > 
> > > AIUI, bcp_sendrow() shouldn't have any effect on the packet.  It only
> > > means, OK, I'm done, that's it for this row.  db-lib reads the bound
> > host
> > > variable buffers, constructs a row image, and feeds it to the regular
> > > packetizer.  As rows are fill the packets, they're sent (with the
> > > more_date indicator).  The only short packet would be at a bcp_batch()
> > > boundary.  
> > > 
> > > If I have any of that wrong, please stop me before I code again....
> > > 
> > > I'm writing a bcp unit test I'll use to debug the problem.  
> > > 
> > > --jkl
> > > _______________________________________________
> > > FreeTDS mailing list
> > > FreeTDS AT lists.ibiblio.org
> > > http://lists.ibiblio.org/mailman/listinfo/freetds
> > 
> > _______________________________________________
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> 
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