On Fri, 2 May 2008 14:19:57 +1000, "John Sheppard" <spam@[EMAIL PROTECTED]
>
wrote:
I am a purist and would not allow bad data in my database. But I'm
also a realist and your suggestion makes some sense. However, I have
seen that the desire to clean up the data disappears as the app is
taken into production and no immediate averse effects are noticed. You
and I know that's just a matter of time...
Also look at it this way. If I have Orders for a CustomerID that no
longer exists, I have limited options:
1: Do research in printed invoices in some filing cabinet and try to
find the missing customer and recreate him. A time-consiming
proposition.
2: Delete the orphans. Most are old. None can be recovered easily.
3: Assign all orphans to CustomerID=-1,
CustomerName=UnknownBadStuffLeftFromEarlierDays
Personally I would keep the Access app for research purposes, and
choose option 2. ˇNo Pasarán!
-Tom.
>Hello there,
>
>I was wondering if anyone could give me some advice on orphaned rows and
>foreign key constraints.
>
>I am migrating a MS-Access database that didnt have any relations setup
>properly, consequently there are gazillions of orphaned tuples.
>
>If I was to leave these as they were and set constraints with NO CHECK is
it
>likly that I am going to run into problems down the track?
>
>Some may shudder that I would consider not cleaning the data but we have
a
>timeline and there is months of cleaning to do, its something I would
prefer
>to do after we make our deadlines.
>
>Thank you
>John Sheppard
>
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