Make database handle persist in CGI/DBI application?

Hi all,

I am writing a Web app in perl/cgi/dbi which (1) attempts to verify
logins by checking against database user passwords, and (2) follows good
dbi practices by logging the user in once at the beginning of the session
instead of logging in immediately prior to accessing the database.

I am running afoul of CGI parameter passing conventions. I do( and
find) the following

use CGI "standard";
use DBI;

my $dbh;
if ($condition){
$dbh = $DBI:connect($connectionString, $login, $password);
# find connection is successful at this poing

sub fubar{

my $sth=$dbh->prepare($cmd);
# find that $dbh is undefined.

I have tried passing the handle in as a ref parameter, using $dbhRef = /*dbh
(maybe this one was done incorrectly) and tried passing a $dbhRef as a
value on a hidden textfield. None of these work. I tend to get
"not an array" when I try to do $$dbhref to dereference the handle.

Is there any way to make the handle persist?
Would I have this trouble if I used Mason?

Thanks in advance,
Mary Anderson

Re: Make database handle persist in CGI/DBI application?

Mary Anderson wrote:
> I have tried passing the handle in as a ref parameter, using $dbhRef = /*dbh
> (maybe this one was done incorrectly) and tried passing a $dbhRef as a
> value on a hidden textfield. None of these work. I tend to get
> "not an array" when I try to do $$dbhref to dereference the handle.
>
> Is there any way to make the handle persist?
> Would I have this trouble if I used Mason?

Mary,
You need mod_perl;

http://perl.apache.org/

Check here first;

http://perl.apache.org/docs/2.0/user/coding/coding.html#C_Mo dPerl__Registry__Handlers_Family

Cheers,
Tyler

Re: Make database handle persist in CGI/DBI application?

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Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: 7bit

Normally you connect like this:

-------------8<-------------
use DBI;
my $dbh = DBI->connect($connectionString, $login, $password);

&foo($dbh);

sub foo {
my $dbh = shift;
my $sth = $dbh->prepare($cmd);
}
-------------8<-------------

Did you thought about using mod_perl there Apache::AuthDBI and
Apache::DBI for persitent database connections and authification.

Tom


Mary Anderson wrote:
> Hi all,
>
> I am writing a Web app in perl/cgi/dbi which (1) attempts to verify
> logins by checking against database user passwords, and (2) follows good
> dbi practices by logging the user in once at the beginning of the session
> instead of logging in immediately prior to accessing the database.
>
> I am running afoul of CGI parameter passing conventions. I do( and
> find) the following
>
> use CGI "standard";
> use DBI;
>
> my $dbh;
> if ($condition){
> $dbh = $DBI:connect($connectionString, $login, $password);
> # find connection is successful at this poing
>
> sub fubar{
>
> my $sth=$dbh->prepare($cmd);
> # find that $dbh is undefined.
>
> I have tried passing the handle in as a ref parameter, using $dbhRef = /*dbh
> (maybe this one was done incorrectly) and tried passing a $dbhRef as a
> value on a hidden textfield. None of these work. I tend to get
> "not an array" when I try to do $$dbhref to dereference the handle.
>
> Is there any way to make the handle persist?
> Would I have this trouble if I used Mason?
>
> Thanks in advance,
> Mary Anderson
>
>
>


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Re: Make database handle persist in CGI/DBI application?

Your CGI is called for each request and then terminated. There is no way
to make the DBI handle persistant. (And by the way, if hiding the handle
in a hidden field would work, you would create a security hole large
enough for a 747.)

You need a permanently running server for a persistant handle. Think
about using FastCGI, Apache::Registry or, if you just have started your
application, a mod_perl handler.

Alexander


Mary Anderson wrote:

>Hi all,
>
> I am writing a Web app in perl/cgi/dbi which (1) attempts to verify
>logins by checking against database user passwords, and (2) follows good
>dbi practices by logging the user in once at the beginning of the session
>instead of logging in immediately prior to accessing the database.
>
> I am running afoul of CGI parameter passing conventions. I do( and
>find) the following
>
>use CGI "standard";
>use DBI;
>
>my $dbh;
>if ($condition){
> $dbh = $DBI:connect($connectionString, $login, $password);
># find connection is successful at this poing
>
>sub fubar{
>
> my $sth=$dbh->prepare($cmd);
># find that $dbh is undefined.
>
>I have tried passing the handle in as a ref parameter, using $dbhRef = /*dbh
>(maybe this one was done incorrectly) and tried passing a $dbhRef as a
>value on a hidden textfield. None of these work. I tend to get
>"not an array" when I try to do $$dbhref to dereference the handle.
>
>Is there any way to make the handle persist?
>Would I have this trouble if I used Mason?
>
>Thanks in advance,
>Mary Anderson
>
>


--
Alexander Foken
mailto:alexander@foken.de http://www.foken.de/alexander/

RE: Make database handle persist in CGI/DBI application?

I have run into this myself The scope of dbh doesn't exist in your sub=
function I make the my $dbh declaration to an our $dbh This s=
eems to do the trick for me. =0AChris -----------------=
------------------------------ Just Your Friendly Neighborhood _S=
PIDEY_ > -----Original Message----- > From: Mary And=
erson [mailto:mfanderson@ucdavisedu] > Sent: Thursday, February 23=
, 2006 12:16 PM > To: dbi-users@perlorg > Subject: Make databa=
se handle persist in CGI/DBI application? > > > Hi all,=0D=
=0A> > I am writing a Web app in perl/cgi/dbi which (1) attempts =
> to verify logins by checking against database user passwords, =0D=
=0A> and (2) follows good dbi practices by logging the user in > once=
at the beginning of the session instead of logging in > immediately =
prior to accessing the database. =0A> > I am running afoul of =
CGI parameter passing conventions I do( and > find) the following=
> > use CGI "standard"; > use DBI; > > my $dbh;=
> if ($condition){ > $dbh =3D $DBI:connect($connectionStrin=
g, $login, > $password); # find connection is successful at this poi=
ng > > sub fubar{ > > my $sth=3D$dbh->prepare($c=
md); > # find that $dbh is undefined. =0A> > I have tried pa=
ssing the handle in as a ref parameter, using > $dbhRef =3D /*dbh (ma=
ybe this one was done incorrectly) and > tried passing a $dbhRef as a=
value on a hidden textfield > None of these work I tend to g=
et "not an array" when I try > to do $$dbhref to dereference the han=
dle. =0A> > Is there any way to make the handle persist? > W=
ould I have this trouble if I used Mason? > > Thanks in advance,=
> Mary Anderson > ----------------------------------=
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