[Developers] South Carolina weirdness

[Nicholas Paldino [.NET/C# MVP]]

	That is a little hokey, IMO.  Why doesn't the operation fail when
trying to set the property to unique if you have more than one of it?
Granted, this idea comes from experience in changing schemas in most RDBM
systems, but it's a concept that absolutely applies here.

	You have to have absolute faith that the data conforms to the
schema.  If it does not, then the schema is absolutely worthless.

          - Nicholas Paldino [.NET/C# MVP]
          - casperOne at caspershouse.com  

-----Original Message-----
From: developers-bounces at freebase.com
[mailto:developers-bounces at freebase.com] On Behalf Of Kurt Bollacker
Sent: Wednesday, June 04, 2008 3:18 PM
To: For discussions about MQL,Freebase API and apps built on Freebase
Subject: Re: [Developers] South Carolina weirdness


On Wed, Jun 04, 2008 at 10:51:01AM -0700, Arthur van Hoff wrote:
> Hi Will,
> 
> I've seen this happen in our code several times. Although the schema 
> allows you to specify properties to have unique values, there does not 
> appear to be strict enforcement of this rule.

It is strict in the sense of creation.  i.e. No multiples of unique
properties can be written once the property becomes unique.
 
> It is very annoying to write all queries assuming that any property 
> (even when it is marked unique) can return multiple values. However, 
> if you don't do this your code is fragile, and will trip up easily in 
> case of a bad insert. I wish there was a better solution.

For types in the main hierarchy, this problem should be very rare.
For user/private types, the problem depends on the creator of the type.

> Have fun,
> 
>     Arthur van Hoff
> 
> 
> > -----Original Message-----
> > From: developers-bounces at freebase.com [mailto:developers- 
> > bounces at freebase.com] On Behalf Of Will Moffat
> > Sent: Wednesday, June 04, 2008 10:21 AM
> > To: Freebase API and apps built on Freebase For discussions about 
> > MQL
> > Subject: [Developers] South Carolina weirdness
> > 
> > Hello,
> > 
> > The trivial query below fails because South Carolina has two values 
> > for "capital" even though the schema says the property must be 
> > unique.
> > This will break applications written against the schema. Are there 
> > tools that warn about this problem? Should they be exposed in the 
> > Freebase UI?
> > 
> > I cannot delete the extra value 'Charleston' using the Freebase.com 
> > UI
> > 
> > Weird thing no. 3 is that I cannot see any record of "capital" ever 
> > being changed in the history view.
> > 
> > http://www.freebase.com/tools/queryeditor/?q=[{"*":null,"type":"/
> > location/us_state"}]
> > http://www.freebase.com/view/en/south_carolina
> > http://www.freebase.com/history/topic/en/south_carolina
> > 
> > regards,
> > --Will
> > _______________________________________________
> > Developers mailing list
> > Developers at freebase.com
> > http://lists.freebase.com/mailman/listinfo/developers
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