[udig-devel] Layer Attribute Query

[Jody Garnett]

Thanks for the example - I will cut and paste it into the wiki for the 
next person.

Jody

Andy Cox wrote:
> Jody,
>
> Thanks for the pointers. I resolved it by using:
>
> CompareFilter filter1 =
> filterFactory.createCompareFilter(Filter.COMPARE_EQUALS);
> 	
> filter1.addLeftValue(filterFactory.createAttributeExpression("SHORT_NAME"));
> 	
> filter1.addRightValue(filterFactory.createLiteralExpression(polygonID1));
> 	        
> CompareFilter filter2 =
> filterFactory.createCompareFilter(Filter.COMPARE_EQUALS);
> 	
> filter2.addLeftValue(filterFactory.createAttributeExpression("SHORT_NAME"));
> 	
> filter2.addRightValue(filterFactory.createLiteralExpression(polygonID2));
>
> Thanks
> Andy
>
> -----Original Message-----
> From: udig-devel-bounces at lists.refractions.net
> [mailto:udig-devel-bounces at lists.refractions.net] On Behalf Of Jody Garnett
> Sent: 16 August 2007 05:27
> To: User-friendly Desktop Internet GIS
> Subject: Re: [udig-devel] Layer Attribute Query
>
> A bit of a warning Andy, code like the following:
>   
>> Feature feature1 = source.getFeatures(filter1).features().next();
>>
>> Feature feature2 = source.getFeatures(filter2).features().next();
>>
>>     
> Will cause lots of problems - you need to call FeatureIterator.close() 
> after you are done using FeatureIterator - otherwise you will end up 
> leaking database connections or holding files open.
>   
>> but I would like to perform an attribute query on a field rather than 
>> an ID query, I am trying a new filter
>>
>>     
> I think you actually mean to check for the "literal" string "CAWSAND DG 
> RAN" ?
>  
>   
>> CompareFilter filter1 = 
>> filterFactory.createCompareFilter(CompareFilter./COMPARE_EQUALS/);
>>
>>
>>     
> filter1.addLeftValue(filterFactory.createAttributeExpression("Short_name"));
>   
>> filter1.addRightValue(filterFactory.createAttributeExpression("CAWSAND 
>> DG RAN"));
>>
>>     
> There should be a filterFactory method for creating a literal - and you 
> can pass in your String.
> Cheers,
> Jody
>
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