org.modeshape.jcr.api.query.qom.SetQueryObjectModel Maven / Gradle / Ivy
/*
* ModeShape (http://www.modeshape.org)
* See the COPYRIGHT.txt file distributed with this work for information
* regarding copyright ownership. Some portions may be licensed
* to Red Hat, Inc. under one or more contributor license agreements.
* See the AUTHORS.txt file in the distribution for a full listing of
* individual contributors.
*
* ModeShape is free software. Unless otherwise indicated, all code in ModeShape
* is licensed to you under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* ModeShape is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this software; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA, or see the FSF site: http://www.fsf.org.
*/
package org.modeshape.jcr.api.query.qom;
import javax.jcr.query.Query;
import javax.jcr.query.qom.QueryObjectModel;
import javax.jcr.query.qom.QueryObjectModelFactory;
/**
* A set query extension to the JCR query object model.
*
* The JCR query object model describes the queries that can be evaluated by a JCR repository independent of any particular query
* language, such as SQL. JCR defines the {@link QueryObjectModel} interface as the primary representatino of this query object
* model, but this interface is not sufficient for certain queries, such as unions or intersections of other queries. This
* interface is an extension to the JCR API that mirrors the QueryObjectModel interface for set queries.
*
*
* A query consists of:
*
* - a source. When the query is evaluated, the source evaluates its selectors and the joins between them to produce a (possibly
* empty) set of node-tuples. This is a set of 1-tuples if the query has one selector (and therefore no joins), a set of 2-tuples
* if the query has two selectors (and therefore one join), a set of 3-tuples if the query has three selectors (two joins), and so
* forth.
* - an optional constraint. When the query is evaluated, the constraint filters the set of node-tuples.
* - a list of zero or more orderings. The orderings specify the order in which the node-tuples appear in the query results. The
* relative order of two node-tuples is determined by evaluating the specified orderings, in list order, until encountering an
* ordering for which one node-tuple precedes the other. If no orderings are specified, or if for none of the specified orderings
* does one node-tuple precede the other, then the relative order of the node-tuples is implementation determined (and may be
* arbitrary).
* - a list of zero or more columns to include in the tabular view of the query results. If no columns are specified, the
* columns available in the tabular view are implementation determined, but minimally include, for each selector, a column for
* each single-valued non-residual property of the selector's node type.
*
*
* The query object model representation of a query is created by factory methods in the {@link QueryObjectModelFactory}.
*
* @see QueryObjectModel
*/
public interface SetQueryObjectModel extends SetQuery, Query {
}