Commit to odbc.c from 5/19/2010 breaks prepared statements with pyodbc
"Peter C. Norton" <[email protected]>
| Newsgroups | gmane.comp.db.tds.freetds |
|---|---|
| Message-ID | <[email protected]> |
Hi, I've got another bug report. At my site we've run into a
regression when going from the following:
pyodbc-2.1.7
depends on
unixODBC-2.2.14
which depends on
freetds-0.82.1.dev.20091223
to the same pyodbc and unixODBC, but upgrading to
freetds-0.83.dev.20100902 + various patches from upstream. When users
tested it I got the following succinct bug report:
import pyodbc
def the_test(db_name):
db = pyodbc.connect("DSN=%s;UID=<USERNAME>;PWD=<PASSWORD>;DATABASE=<any database>;APP=python_test" % db_name)
q = db.execute("select * from <any table> where type = ?", (1,))
print q.fetchall()
the_test("SYBASE")
results in the following error:
Error: ('HY000', 'The driver did not supply an error!')
Confirmed on solaris x86 and linux/64-bit. I've bisected the changes
made back to 5/19/2010 via the freetds git repository and I found that
the following broke prepared statements from pyodbc:
http://github.com/brianb/FreeTDS/commit/2ed78ea4dd9018927b56822e318e0b5ac9401b98#diff-2
Specifically the chunk between line 1301 and 1313. The relevent chunk of code is this:
if (desc->type == DESC_IRD && ((TDS_STMT*)desc->parent)->need_reprepare && \
odbc_update_ird((TDS_STMT*)desc->parent, errs) != SQL_SUCCESS) \
exit; \
Reverting the patch to the pre-2010-05-19 state has the preprocessor
replace the above with:
#define IRD_UPDATE(desc, errs, exit) do { } while(0)
which may just be masking an error, but I do not know. Backing this
out causes prepared statements to work again. Are there any gotchas
to reverting this change? And is there a better/more correct fix for
this?
By the way, this works fine when I point the same test an an MSSQL 2005 or 2008 server.
Thanks,
-Peter