[python-sybase] RE: Sybase Module 0.36 Output Parameter Handling

[Dave Cole]

Dave Cole wrote:
> Dave Cole <djc@object-craft.com.au>Dave Cole 
> <djc@object-craft.com.au>Dave Cole wrote:
> 
>> I just installed ASE 12.5.2 on my machine so I could do some testing. 
>> It appears there is a problem with the Cursor.callproc() method, but 
>> only when you use a sequence to pass parameters.  Dictionary 
>> parameters are fine.
>>
>> The attached sp_test.py program shows my testing.
>>
>> This program produces the following output (after applying the 
>> attached callproc.patch to fix sequence argument passing).
>>
>> {'@num': 12345, '@result': 12345}
>> [54321, 54321]
>>
>> If I remove the comment character from the code that enables the 
>> debugging I get the output contained in the attached sp_test.log.
>>
>> So if it is not working with FreeTDS then they are doing something 
>> slightly differently that is either confusing my code or is incorrect.
> 
> 
> I just installed FreeTDS 0.61 (Debian sarge) and the test program fails 
> to run.  The ct_param() functions fail.  What I did discover was that 
> you can fudge it like this:
> 
> print db.execute('''
> declare @result int
> exec sp_test_output 12345, @result output
> select @result
> ''')
> 
> It prints the following:
> [[], [(12345,)]]
> 
> I am now downloading the current cvs snapshot for FreeTDS to see if they 
> have fixed parameter passing.

I just downloaded and installed the CVS snapshot.  With the original 
test program it appears to send the parameters to the server but fails 
with a server message.

Looking at the debug log:

Cursor.callproc
ct_cmd_alloc(conn0, &cmd) -> CS_SUCCEED, cmd3
ct_command(cmd3, CS_RPC_CMD, "sp_test_output", CS_NULLTERM, CS_UNUSED) 
-> CS_SUCCEED
ct_param(cmd3, &databuf0->fmt=[name:"@result" type:CS_INT_TYPE 
status:CS_RETURN format:CS_FMT_UNUSED count:1 maxlength:4 scale:0 
precision:0], databuf0->buff, 4, 0) -> CS_SUCCEED
ct_param(cmd3, &databuf1->fmt=[name:"@num" type:CS_INT_TYPE 
status:CS_INPUTVALUE format:CS_FMT_UNUSED count:1 maxlength:4 scale:0 
precision:0], databuf1->buff, 4, 0) -> CS_SUCCEED


So it appears that parameters are being accepted by FreeTDS but from the 
next debug lines, they are not being sent correctly.


ct_send(cmd3) -> CS_SUCCEED
servermsg_cb
Msg 245, Level 16, State 1, Procedure sp_test_output
Domain error during implicit conversion of DECIMAL value '' to a INT field.
servermsg_cb
Msg 245, Level 16, State 1, Procedure sp_test_output
Domain error during implicit conversion of DECIMAL value '' to a INT field.
ct_results(cmd3, &result) -> CS_SUCCEED, CS_STATUS_RESULT
ct_cancel(conn0, NULL, CS_CANCEL_ALL) -> CS_SUCCEED
Traceback (most recent call last):
   File "a.py", line 21, in ?
     r = c.callproc('sp_test_output', {'@num': 12345, '@result': 
Sybase.OUTPUT(1)})
   File "/usr/lib/python2.3/site-packages/Sybase.py", line 718, in callproc
     self.description = fetcher.start(self.arraysize, out_params)
   File "/usr/lib/python2.3/site-packages/Sybase.py", line 391, in start
     return _FetchNow.start(self, arraysize)
   File "/usr/lib/python2.3/site-packages/Sybase.py", line 315, in start
     raise e
Sybase.DatabaseError: Msg 245, Level 16, State 1, Procedure sp_test_output
Domain error during implicit conversion of DECIMAL value '' to a INT field.
Msg 245, Level 16, State 1, Procedure sp_test_output
Domain error during implicit conversion of DECIMAL value '' to a INT field.

Even more worrying is that the fudge in the previous message no longer 
works.  I get crap back.

Oh well, looks like I can wait for another couple of FreeTDS releases 
before trying again...

- Dave

-- 
http://www.object-craft.com.au