[freetds] bug/change in behavior in handling null text columns
John Mund
jmund at miqs.com
Thu May 24 11:34:34 EDT 2007
Hello,
There is a difference between .63 and .64 versions on how null text
columns are handled. I believe it is a bug. When you have a text
column that previously had a value and then was set to null,
freetds-0.64 doesn't appear to treat it as null, but rather some kind of
zero length string. This causes problems downstream (php blows up).
Version .63 correctly treated it as null.
Here are the details:
Platform/OS: Intel/FreeBSD 6.2
freetds-0.64
Connecting to remote Sybase DB (same behavior on versions 11.9.2 and 15)
Sybase @@version:
Adaptive Server Enterprise/11.9.2.6/1290/P/EBF 10491
ESD1/Sun_svr4/OS 5.5.1/FBO/Mon Jul 15 06:54:22 2002
Adaptive Server Enterprise/15.0/EBF 13194 EC ESD/P/Linux
Intel/Linux 2.4.21-20.ELsmp i686/ase150/2179/32-bit/FBO/Mon Feb 6
04:14:19 2006
To reproduce in tsql
1> create table #t (t1 text null, t2 text null)
2> insert #t (t1) select "a"
3> select * from #t
4> go
t1 t2
a NULL
1> update #t set t1=null
2> select * from #t
3> go
t1 t2
NULL
The value for t1 is a blank, but not a null. I believe this should be a
NULL. The same sql to same databases (from Intel/FreeBSD 5.4) using
freetds-0.63 results in:
t1 t2
NULL NULL
Please let me know if I can provide any more details.
Thank you for your work on this great piece of software.
John
More information about the FreeTDS
mailing list