Re: Delete function disabled

On Thu, Nov 24, 2011 at 11:02 AM, Colin Beckingham <colbec@start.ca> wrote:
>
>
> On 11/24/2011 04:59 AM, Dave Page wrote:
>>
>> On Thu, Nov 24, 2011 at 9:53 AM, Colin Beckingham<colbec@start.ca>  wrote:
>>>
>>>
>>> On 11/24/2011 03:52 AM, Nick Rogers wrote:
>>>>
>>>> I use pgAdmin v1.14.0 multiple databases stored on multiple servers. I
>>>> am able to use the GUI to insert rows and edit existing rows. But when
>>>> it comes to deleting rows, I am forced to manually type in the SQL to
>>>> delete the rows because the "Delete" toolbar button is disabled as well
>>>> as the "Delete" item in the "Edit" menu. This is the case for all of the
>>>> servers I connect to, including localhost. Why is this happening?
>>>>
>>>> Thanks!
>>>
>>> I get this as well. However if the table has OIDs then the delete button
>>> activates no problem.
>>
>> It needs either a primary key or OIDs to allow deletes. By default,
>> you'll get a guru hint warning you that you need one of them when you
>> first open a table without, but it's possible to suppress that hint
>> and then forget about it 12 months later :-)
>>
>
> Correctamundo. Thanks for the reminder.
>
> It seems a bit strict... Presumably lots of thinking went into this -
> without a unique key, any delete statement might delete multiple duplicate
> rows without a limit statement, which might or might not be what the user
> intended.

Right - a unique key with not-null on every attribute is required to
avoid potential disaster. We currently just use a pkey (or OIDs), but
the code could potentially be enhanced to support individual
constraints that can guarantee uniqueness. That's not trivial though,
and frankly it's good practice to define a pkey anyway.


--
Dave Page
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