l i n u x - u s e r s - g r o u p - o f - d a v i s
L U G O D
 
Next Meeting:
December 2: Social gathering
Next Installfest:
TBD
Latest News:
Nov. 18: Club officer elections
Page last updated:
2005 Mar 18 15:23

The following is an archive of a post made to our 'vox-tech mailing list' by one of its subscribers.

Report this post as spam:

(Enter your email address)
Re: [vox-tech] BSD versus Linux (and SQL/PHP/magic quoting)
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [vox-tech] BSD versus Linux (and SQL/PHP/magic quoting)



--Signature_Fri__18_Mar_2005_14_20_53_-0800_.10VX0K9+AEr7yEs
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: quoted-printable

On Fri, 18 Mar 2005 15:08:47 -0500
David Hummel <dhml@comcast.net> wrote:

> On Fri, Mar 18, 2005 at 04:01:13PM +0000, Ken Bloom wrote:
> >=20
> > On Fri, 18 Mar 2005 10:57:34 -0500
> > p@dirac.org (Peter Jay Salzman) wrote:
> > >=20
> > >    http://www.dirac.org/linux/sql_quoting.html
> >=20
> > Does PHP not have ?-parameter substitution (so you can say
> > SELECT * FROM table WHERE stringattribute=3D?
> > and substitute the ? with a string that is properly quoted according
> > to the language conventions?
>=20
> Also known as placeholders (?) and bind values (the substituted
> value). But the way you've written it does not account for binding
> undefined values (which are usually bound as NULL):
>=20
> SELECT * FROM table WHERE stringattribute =3D NULL
>=20
> This will not select stringattribute's that are NULL.  To do that you
> would say:
>=20
> SELECT * FROM table WHERE stringattribute IS NULL
>=20
> Unless you know for certain that you are never binding undefined
> values, you can use the following to avoid this problem:
>=20
> SELECT * FROM table WHERE ((? IS NULL AND stringattribute IS NULL) OR
> stringattribute =3D ?)
>=20
> and then bind the same value to both placeholders.

Binding a NULL to a ? is no different from putting the NULL right in the
string - it still has the same problem with the =3D operator, and that is
completely orthagonal to my discussion of placeholders and bind values.

--Ken Bloom


--=20
I usually have a GPG digital signature included as an attachment.
See http://www.gnupg.org/ for info about these digital signatures.

--Signature_Fri__18_Mar_2005_14_20_53_-0800_.10VX0K9+AEr7yEs
Content-Type: application/pgp-signature

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.0 (GNU/Linux)

iD8DBQFCO1ROlHapveKyytERArWKAJ90D7amMbDt4Dys/Kl1nhIIQ6/7sQCeMuvF
Wv4zaPjuugvTdhwWdR2qPB4=
=LyUj
-----END PGP SIGNATURE-----

--Signature_Fri__18_Mar_2005_14_20_53_-0800_.10VX0K9+AEr7yEs--

_______________________________________________
vox-tech mailing list
vox-tech@lists.lugod.org
http://lists.lugod.org/mailman/listinfo/vox-tech


LinkedIn
LUGOD Group on LinkedIn
Sign up for LUGOD event announcements
Your email address:
facebook
LUGOD Group on Facebook
'Like' LUGOD on Facebook:

Hosting provided by:
Sunset Systems
Sunset Systems offers preconfigured Linux systems, remote system administration and custom software development.

LUGOD: Linux Users' Group of Davis
PO Box 2082, Davis, CA 95617
Contact Us

LUGOD is a 501(c)7 non-profit organization
based in Davis, California
and serving the Sacramento area.
"Linux" is a trademark of Linus Torvalds.

Sponsored in part by:
Sunset Systems
Who graciously hosts our website & mailing lists!