I believe Larry is correct. A database "null" and a null Java
reference are not the same thing. I'm not absolutely sure about this,
but I bet one of our database wizards could confirm.
The Sunburned Surveyor
On Wed, Apr 29, 2009 at 7:44 AM, Larry Becker <becker.la...@gmail.com> wrote:
> >From the point of view of BasicFeature, there is no distinction between the
> geometry and any other attribute. All modifications are still funneled
> through setAttribute(). For example the setGeometry() code in
> AbstractBasicFeature is:
>
> public void setGeometry(Geometry geometry) {
> setAttribute(schema.getGeometryIndex(), geometry);
> }
>
> Larry
>
> On Wed, Apr 29, 2009 at 8:50 AM, Rahkonen Jukka <jukka.rahko...@mmmtike.fi>
> wrote:
>>
>> Hi.
>>
>> What might happen if it is the geometry that is null in the database? It
>> is rather common situation sometimes, it is quite possible that we know for
>> example parcel attributes beforehand and we should just digitise the borders
>> afterwards.
>>
>> The DB Query plugin (or should those plugins be called as extensions?)
>> from
>> http://jumpdbqplugin.sourceforge.net/
>> is building a default geometry is database does not return a real one.
>> Geometry is for example like
>> POLYGON ((0.1 0.1, -0.1 0.1, -0.1 -0.1, 0.1 -0.1, 0.1 0.1))
>>
>>
>> This works fine for reading from the database, I am not clever
>> enough even to think about what happens if database access is read/write.
>>
>> WFS is another datasource that can return attributes without geometry.
>>
>> -Jukka Rahkonen-
>>
>> Larry Becker wrote:
>>
>> > > But what if the initial value for a certain attribute was indeed
>> > NULL???
>> >>
>> >> Data coming from a database can contain NULLs...
>>
>> > In that case, I believe the attribute object[] array would contain an
>> > object that
>> > references null and not null reference, if that distinction is clear.
>> > They should
>> > still be typed Objects as in:
>>
>> > String column1 = null; Double column2 = null;
>>
>> > Larry
>>
>> >> On Tue, Apr 28, 2009 at 3:29 PM, Paolo Rizzi <g...@oicom.com> wrote:
>>
>> >> In the code inside my previous post I used the value "this" as a flag
>> >> but maybe that was bad!!! That way the BasicFeature could live
>> forever,
>> >> or maybe not if garbage collectors are smarter these days...???
>>
>> >> Anyway the point was to use a reference to any already existing Object
>> >> as a flag, so to not create a new Object for the purpose. But any
>> >> Object, existing or created anew would do. Obviously if
>> >> initialialization never ends for any reason, both the mods array and
>> the
>> >> flag Objects it points to, are never released.
>>
>> >> Bye
>> >> Paolo
>>
>>
>>
>>
>>
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>
>
>
> --
> http://amusingprogrammer.blogspot.com/
>
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