Checking data inserted during a transaction

Hello all,

I'm working on an administrative interface in PHP for the art gallery
database I created last year, and running into a few issues.

Because information has to be entered into several different tables for each
exhibition, I've broken down the process of adding new exhibitions to the
databases into several pages, each of which processes the form data sent
from the previous page and then guides users through the next step (artists
featured in the exhibition, etc.).

I'm using transactions to handle this, so that at the end of the process the
user can (hopefully) review the data they've entered and either commit or
rollback the changes. But I'm having a bit of trouble figuring out whether
the data I'm trying to insert during the transaction is actually being
inserted.

From what I've read about transactions thus far, it looks to me as though
the data inserted should be visible in the database after the insert is done
but before the commit or rollback happens, and then disappear if rollback is
chosen. But that doesn't seem to be working.

I've loaded the data from the first form into an associative array, added
the name of the user who created and last modified the record (at this
stage, the same user) and the date created and last modified (again, the
same date, since this is the form for adding a new record), and printed the
array to make sure all the data is correct. Then I've used the following
statement to try and load it into the exhibitions table of the database:

$exh_query = pg_insert($db, 'exhibitions', $exh_info)
or die ("Unable to insert data.");

$db is the database connection, and $exh_info is the array, which I've
already tested and made sure is working. Everything appears to go smoothly,
it doesn't die, no error message is generated - but the new row does not
show up in phpPgAdmin when I check there.

Have I done something wrong? Or am I confused and does data entered during a
transaction not actually show up until the commit? If that's the case, is
there any way I can display all the data for the user to review at the end
of the process before committing the changes? I was planning to pull it from
the database for that, but if it's not *in* the database, I can't do that.

And if I can't, is there perhaps some way to pass an array from one page to
the next for several pages, adding to it along the way? I know you can do
that with normal variables through either hidden form fields or putting them
in the URL, but I don't know about arrays... And at least one of the fields
(exhibition_description) is potentially several paragraphs long.

Any advice would be appreciated...

Thanks,

Lynna

P.S. My web host is running PHP 4.3.4 and PostgreSQL 7.4 if that's a factor.

--
Resource Centre Database Coordinator
Gallery 44
www.gallery44.org