org.jrdf.query.relation.operation
Interface Project

All Known Implementing Classes:

ProjectImpl

public interface Project

Derives a new relation by removing attributes. The list of attributes may either be the set of attributes to include or the list of attributes to exclude.

Version:

$Revision: 1045 $

Author:

Andrew Newman

Method Summary

Relation	exclude(Relation relation, Set<Attribute> attributes) The attributes to exclude in the project.
Relation	include(Relation relation, Set<Attribute> attributes) The attributes to include in the projection.

Method Detail

include

Relation include(Relation relation,
                 Set<Attribute> attributes)

The attributes to include in the projection. This is the usual idea of project found in SQL's SELECT for example. Will overwrite any existing inclusion or exclusion.

Parameters:

attributes - the set of attributes to keep during projection.

exclude

Relation exclude(Relation relation,
                 Set<Attribute> attributes)

The attributes to exclude in the project. Will overwrite any existing inclusion or exclusion.

Parameters:

attributes - the set of attributes to remove during projection.