[postgis-users] OIDS, PostGIS and Quantum GIS

[Ben Madin]

Juan,

Agreed that this can be annoying (especially in light of some other  
GIS packages which don't seem to care at all, or for instance  
shapefiles.

I have had the same frustration when constructing geometries in a  
query or for a view, or any type of aggregate query really. This is  
also a problem for querymaps in MapServer.

The alternative I settled with was creating a false key - for instance  
if the view was a makeline from points, making an id that was the gid  
of the first * 100000 + the gid of the second.

That may help. It may not - but there are better minds than mine  
hovering nearby, so I look forward to their suggestions.

cheers

Ben


On 08/05/2009, at 7:36 PM, Andreas Neumann wrote:

> hm - what's wrong with having a primary key in every table? Good DB- 
> Design
> requires primary keys. Other tools will refuse to work with your  
> data if
> you don't use primary keys as well. As an example, pgadmin3 requires a
> primary key if you want to edit the data in the grid view.
>
> If you use the datatype "serial" or a sequence it is not complicated  
> at
> all to use primary keys.
>
> Andreas
>
> On Fri, May 8, 2009 1:18 pm, Juan Pedro Pérez Alcántara wrote:
>> Hello,
>>
>> perhaps this is a silly one, but I'm having a hard time dealing with
>> primary keys restrictions in Quantum GIS. Not always is possible or
>> desirable to put a, sometimes, artificial int4 PK in some tables  
>> only to
>> be able to load them in QGIS. Those restrictions are very  
>> frustrating.
>>
>> I have been messing around for a solution, and I have experimented  
>> with
>> OIDS. This seems to be enough for QGIS, but I fear the behavior of  
>> OIDS.
>> I don't like the idea of non-controlled PK in my tables. So my  
>> question
>> is simple: does creating a table WITH OIDS means that the OIDS will  
>> be
>> part of the PK of the table like you it or not, or you have to  
>> specify
>> that the OIDS are part of the PK in the ADD CONSTRAINT statement?
>>
>> My hope is that PostgreSQL uses internally OIDS without interfering  
>> with
>> the true PK of the table, while QGIS is happy by having them around.
>> OIDS will not play any role in my model other than that.
>>
>> Greetings,
>>
>> Juan Pedro Pérez Alcántara
>>
>>
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>>
>
>
> -- 
> Andreas Neumann
> http://www.carto.net/neumann/
> http://www.svgopen.org/
>
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Ben Madin
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