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Re: [udig-devel] Accessing selected feature attributes
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You mean it's using my windows username at this point, even though the
initial connection was made with the default postgres account? It's
weird - I tried changing rights on the relevant DB and geometry_columns
table to match my OS username but not effect. Ah well - it's not that
critical right now.
The code snippet is very helpful...
cheers
Murray
Jesse Eichar wrote:
On 11-Jan-07, at 1:57 PM, Murray Richardson wrote:
Jesse or others,
A couple quick questions for you:
(1) Is there a simple way to return attributes (say FID) for all
selected features in a layer? I would like to use these values in
statements to postgreSQL. I'm not clear on how to get them from the
Layer Filter.
To get the selected features:
Suppose you just want the FID:
ILayer layer=null;
// first create a query that restricts the attributes returned.
Since we just want the FID then we don't need
// any attributes because that is not an attribute it part of
the Feature itself.
// also use the Layer.getFilter() method to return the selected
features.
// the new String[0] parameter indicates that we don't want any
attributes. We could have put an attribute/column
// name to indicate the attributes that we want.
Query query = new DefaultQuery(layer.getSchema().getTypeName(),
layer.getFilter(), new String[0]);
IProgressMonitor monitor;
FeatureSource featureSource =
layer.getResource(FeatureSource.class, monitor);
FeatureCollection features = featureSource.getFeatures(query);
FeatureIterator featureIterator = features.features();
try{
while(featureIterator.hasNext() ){
Feature feature=featureIterator.next();
// do something.
// the features here will have no attributes or geometry but you can
call getID().
// warning you can't call getBounds() cause there's no geometry. this
is a bug that still needs to be fixed
}
}finally{
// don't forget to close the iterator...
featureIterator.close();
}
Here's an example of a Query that requests the attribute called streetname:
Query query = new DefaultQuery(layer.getSchema().getTypeName(),
layer.getFilter(), new String[]{streername});
(2) Create Feature Type operation doesn't work on the postGISdataStore
that I access through my postGIS host in the catalog tree. I get a
"Failed to create Feature Type" error. This could be handy. Is there
a simple solution?
Are you talking about the operation that you get when you right-click on
a PostGis in the catalog? If so this probably means that as a user you
don't have the access to make a feature type. I have tested it before
and it does work, but it does require permission to create tables and to
modify the Geomtrycolumns table. I don't know if it works on pre 8.1
versions of Postgres.
Thanks,
Murray
_______________________________________________
User-friendly Desktop Internet GIS (uDig)
http://udig.refractions.net
http://lists.refractions.net/mailman/listinfo/udig-devel
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_______________________________________________
User-friendly Desktop Internet GIS (uDig)
http://udig.refractions.net
http://lists.refractions.net/mailman/listinfo/udig-devel
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