[Phpmyadmin-devel] nested forms problem

[Alexander M. Turek]

Hi Marc, Garvin & list,

Garvin Hicking wrote:
> 
> > since the addition of the multi-row delete (and edit) 
> > feature, we have a nested forms situation when 
> > PMA_linkOrButton() decides that (probably due to a missing 
> > primary key), a generated link would be too long, and creates 
> > a mini form instead.
> 
> I just read that item, and I was shocked. I almost completely 
> forgot about this. :-)
> 
> I see a general problem with the form method. When we place 
> them all in a huge loop it will create huge amounts of POST 
> data, which can lead to timeouts or POST-size limits when 
> dealing with blob-fields without primary keys.

It's not only that: depending on how many fields the user defined for his
table, the form itself could be too huge if many records are selected.

Sounds like a task to work on for 2.5.7 ;-)

What about displaying the forms page-wise?
The user would get the form for the first record he selected. In this form,
we would include some hidden input fields that store the keys of those
records that haven't been edited yet.

When the user submits the form for the first record, we would perform the
UPDATE query and

- display the first form again, if the UPDATE query fails, or
- display the form for the next record otherwise

and so on. This way, we would get around large HTML forms and POST data.

I also wonder about another optimization:
If the user has defined a unique key over NOT NULL coloumns only, we should
be able to use this one instead of the primary key. Of course, this only
makes sense, if the unique key is smaller than the primary one.

> 
> Regarding the note above I see too many possible problems and 
> I think it would be best to disable multi-row for that cases.

+1 from my side.

> Additionally I think a visible (but not disturbing) message 
> should be generated on screen which tells the user that he 
> SHOULD put a primary key on his column.
> 

I fully agree.

Perhaps we should also warn the user if he has created a new table without
any primary or unique keys.

Anyway, I suggest to add a small note about this issue to our README and /
or release notes for 2.5.6.

Regards,

-- 

Alexander M. Turek
<rabus at users.sourceforge.net>

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