Re: remove gaps in a table

From: The Natural Philosopher <tnp_at_invalid.invalid>
Date: Wed, 20 Dec 2017 18:23:02 +0000
Message-ID: <p1e9q7$k8m$1_at_dont-email.me>


On 20/12/17 00:01, mireero wrote:
> On 12/20/2017 12:29 AM, J�rgen Exner wrote:

>> On Tue, 19 Dec 2017 22:03:16 +0100, mireero <mireero_at_free.fr> wrote in
>> comp.databases.mysql:
>>
>> [...]
>>> I'm looking for a way to "reduce" the order_number, to remove gaps, that
>>> is to obtain:
>> [...]
>>> I guess we could just iterate on all rows and set the order_number,
>>> beginning from 1 but I have the feeling I'm missing something.
>>>
>>> Note: in the real table, there are thousands of rows.
>>
>> Are you sure this is a good idea? I just imagine a customer calling:
>>
>> "Good morning. This is ACME Corporation customer support. How may I help
>> you".
>> "Good morning. We have an issue with our last order. The order number is
>> 12345".
>> "Just a second, let me look this up. Ah, yes, I see. What is the problem
>> with the 50 anal beads?"
>> "Anal beads? This is the Jesuit Convent of xyz and I am calling about
>> the order for 30 rosaries!".
>>
>> jue
>>

>
> Thanks for all the answers.
>
> I do get the idea, don't store the order_number in the database.
> It's seducing (by the way, I need to be sure that no order will be
> deleted in the future).
>
> But still, if the order_number is not stored, how would I fetch an order
> just knowing the order_number (and the month) ?

It is not a question of not storing it, it is a question of never altering it once stored.

Once a transaction has been committed, you CANNOT change it, in business. You may issue a reversal - i.e. a credit note. but you cannopt change and order NUMBER. You might amend details

Ots the sam,e with part numbers in a materials stiore. New part numbers are always issued - old ones are never re-used.

How many times have you seen 'KP 756747 superseded by part number XF 4571086' and so on?

-- 
There’s a mighty big difference between good, sound reasons and reasons 
that sound good.

Burton Hillis (William Vaughn, American columnist)
Received on Wed Dec 20 2017 - 19:23:02 CET

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