com.sap.cds.ql.hana.HierarchySubset Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of cds4j-api Show documentation
CDS4J API
There is a newer version: 3.6.1
/*******************************************************************
 * © 2024 SAP SE or an SAP affiliate company. All rights reserved. *
 *******************************************************************/
package com.sap.cds.ql.hana;

import com.google.common.annotations.Beta;
import com.sap.cds.ql.Source;
import com.sap.cds.ql.TableFunction;
import com.sap.cds.ql.cqn.CqnPredicate;

/**
 * A function to compute the subset of a source hierarchy, which contains all
 * nodes relative (ancestors or descendants) to a set of start nodes.
 * 
 * The function adds the element {@code hierarchy_distance : Int32} to
 * the result, which indicates the distance of the retained node from the start
 * node.
 * 
 * Nodes can occur multiple times in the result if they are reachable from
 * multiple start nodes.
 */
@Beta
public interface HierarchySubset extends CqnHierarchySubset, TableFunction {

	/**
	 * Creates a copy of this hierarchy subset function with the given source.
	 * 
	 * @param source the hierarchy source
	 * @return new hierarchy subset function with given source
	 */
	HierarchySubset copy(Source source);

	/**
	 * 
	 * Specifies a filter condition that identifies the start nodes of this
	 * hierarchy subset function.
	 * 
	 * @param startWhere the filter condition that specifies the start nodes
	 * @return this hierarchy subset function
	 */
	HierarchySubset startWhere(CqnPredicate startWhere);

	/**
	 * Specifies a minimum and a maximum HIERARCHY_DISTANCE
	 * 
	 * @param from the minimum distance
	 * @param to   the maximum distance
	 * @return this hierarchy subset function
	 */
	HierarchySubset distance(int from, int to);

	/**
	 * Specifies a minimum HIERARCHY_DISTANCE
	 * 
	 * @param from the minimum distance
	 * @return this hierarchy subset function
	 */
	HierarchySubset from(int from);

	/**
	 * Specifies a maximum HIERARCHY_DISTANCE
	 * 
	 * @param to the maximum distance
	 * @return this hierarchy subset function
	 */
	HierarchySubset to(int to);

	/**
	 * Specifies a maximum absolute HIERARCHY_DISTANCE
	 * 
	 * @param distanceFromStart the maximum absolute HIERARCHY_DISTANCE
	 * @param keepStart         whether the start nodes should be included
	 * @return this hierarchy subset function
	 */
	HierarchySubset distance(int distanceFromStart, boolean keepStart);

}