freebcp native format doesn't work

[mmcnabb-vms]

Testing with Branch-1_5, commit 0f7966d in Windows 11 + Visual Studio 17.13.6:

Using the following command with any table (here I used the pubs2 demonstration database that comes with the SAP ASE 16.0 free trial):

freebcp pubs2.dbo.sales out sales_n.txt -Ssybase -Usa -Ppassword -n

produces error output:

 Msg 20060, Level 11
 Unknown datatype encountered

 Error in bcp_colfmt col 1

The same command with -c instead of -n works correctly for both in and out; but -n fails in both cases. I have tried various other column configurations and get the same error in all cases. The bcp utility that comes with SAP ASE SDK 16.0 works correctly in both cases.

Using the debugger, the error code is generated by the following code in freebcp.c 's function file_native() :

for (i = 1; i <= li_numcols; i++) {
	li_coltype = dbcoltype(dbproc, i);

	if (bcp_colfmt(dbproc, i, li_coltype, -1, -1, NULL, -1, i) == FAIL) {
		fprintf(stderr, "Error in bcp_colfmt col %d\n", i);

and the value of li_coltype is -1 when i is 1, which leads to a call is_tds_type_valid(-1) which gives false.
The dbcoltype function returns -1 due to the code in dblib.c:

info = tds->res_info;
if (!info)
	return NULL;

and res_info is null here.

[freddy77]

Which is the structure of pubs2.dbo.sales table?

[mmcnabb-vms]

@freddy77 See sales Table

I tried a variety of tables and got the same error in all cases -- are you having trouble reproducing it?

[glennc83]

We had the same problem - so we changed our code to use the datacopy utility instead of bcp.

[mmcnabb-vms]

Same issue occurs with SQL Server. Note - the column type check inside bcp_init() works correctly.

Further debugging seems to show a logic error in file_native: the call to dbresults() invokes tds_free_all_results(tds); on receipt of the TDS_DONE_RESULT state as expected. This causes tds->res_info to become NULL and therefore the subsequent check of dbcoltype fails.

This freeing of results was added in commit: 9058123. Reverting that commit does fix this issue, but (as expected) makes the test d_empty_rowsets fail, because that test explicitly checks that an empty SELECT should leave a state with 0 columns (which is of course incompatible with freebcp's requirements where it explicitly performs an empty SELECT in order to get column data).

I do not see what the purpose of that commit is; it only has the comment "can produce an incorrect resultset" without elaborating on why or how -- an empty result set does not seem incorrect per se. Perhaps there is another way to fix thatever that problem was.

There is not currently a test in the test suite for this; #683 blocks creation of such tests .

[mmcnabb-vms]

I have a proposed fix coming for this and for #648 tomorrow

[mmcnabb-vms]

PR #684 covering this issue and #648 . I have rebased it just now in case the recent 'master' pushes regarding the Windows build system fix the failed appveyor tests originally (and so that I have those changes present for work on #478) .

See also #686