[thelist] PHP/MySQL help

Hi all.

I've got a weird one.

I've got a mySQL database that was behaving perfectly well.

It's updated by some PHP forms - read it, allow editing, save changes
etc.

All that was working fine.

there's a field (vcategory) in the item table that is for future
purposes, it's set up as int(11) null=yes default 0 (reading the
PHPmyadmin table view)

we've been doing database updates outside the PHP - importing records
and somehow the vcategory fields on most of the records are now empty.
(i.e contain nothing)

If I try to edit these records (in my PHP forms) the save doesn't "take"

but if I edit the record (in PHPmyadmin or my forms) and set vcategory
to 0 the save does "take".

Can anyone shed any light on why this might be?

I guess all I have to do is update the field to 0 and then all my
records will become editable again, but I'd really like to know why this
one thing would cause an update to fail.

Cheers

Tony