dk.eobjects.metamodel.query.GroupByItem Maven / Gradle / Ivy

Go to download
/**
 *  This file is part of MetaModel.
 *
 *  MetaModel is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  MetaModel 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 General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with MetaModel.  If not, see .
 */
package dk.eobjects.metamodel.query;

import org.apache.commons.lang.builder.EqualsBuilder;

/**
 * Represents a GROUP BY item. GroupByItems always use a select item (that may
 * or not be a part of the query already) for grouping.
 * 
 * @see GroupByClause
 */
public class GroupByItem implements IQueryItem, Cloneable {

	private static final long serialVersionUID = 5218878395877852919L;
	private SelectItem _selectItem;
	private Query _query;

	/**
	 * Private constructor, used for cloning
	 */
	private GroupByItem() {
	}

	/**
	 * Constructs a GROUP BY item based on a select item that should be grouped.
	 * 
	 * @param selectItem
	 */
	public GroupByItem(SelectItem selectItem) {
		if (selectItem == null) {
			throw new IllegalArgumentException("SelectItem cannot be null");
		}
		_selectItem = selectItem;
	}

	public SelectItem getSelectItem() {
		return _selectItem;
	}

	@Override
	public String toString() {
		StringBuilder sb = new StringBuilder();
		sb.append(_selectItem.getSameQueryAlias());
		return sb.toString();
	}

	@Override
	public boolean equals(Object obj) {
		if (obj == this) {
			return true;
		}
		if (obj instanceof GroupByItem) {
			GroupByItem that = (GroupByItem) obj;
			EqualsBuilder eb = new EqualsBuilder();
			eb.append(this.getSelectItem(), that.getSelectItem());
			return eb.isEquals();
		}
		return false;
	}

	public Query getQuery() {
		return _query;
	}

	public GroupByItem setQuery(Query query) {
		_query = query;
		if (_selectItem != null) {
			_selectItem.setQuery(query);
		}
		return this;
	}

	@Override
	protected GroupByItem clone() {
		GroupByItem g = new GroupByItem();
		g._selectItem = _selectItem.clone();
		return g;
	}
}