Mercurial > hg > release > thermostat-0.15
view storage/core/src/main/java/com/redhat/thermostat/storage/core/AggregateQuery.java @ 1218:e2034aa58edf
Implement aggregate prepared query (count).
Reviewed-by: omajid
Review-thread: http://icedtea.classpath.org/pipermail/thermostat/2013-August/007834.html
PR1509
author | Severin Gehwolf <sgehwolf@redhat.com> |
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date | Fri, 09 Aug 2013 10:43:36 +0200 |
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/* * Copyright 2012, 2013 Red Hat, Inc. * * This file is part of Thermostat. * * Thermostat 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 2, or (at your * option) any later version. * * Thermostat 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 Thermostat; see the file COPYING. If not see * <http://www.gnu.org/licenses/>. * * Linking this code with other modules is making a combined work * based on this code. Thus, the terms and conditions of the GNU * General Public License cover the whole combination. * * As a special exception, the copyright holders of this code give * you permission to link this code with independent modules to * produce an executable, regardless of the license terms of these * independent modules, and to copy and distribute the resulting * executable under terms of your choice, provided that you also * meet, for each linked independent module, the terms and conditions * of the license of that module. An independent module is a module * which is not derived from or based on this code. If you modify * this code, you may extend this exception to your version of the * library, but you are not obligated to do so. If you do not wish * to do so, delete this exception statement from your version. */ package com.redhat.thermostat.storage.core; import com.redhat.thermostat.storage.model.Pojo; import com.redhat.thermostat.storage.query.Expression; /** * Common super class for aggregate queries. */ public abstract class AggregateQuery<T extends Pojo> implements Query<T> { public enum AggregateFunction { /** * Aggregate records by counting them. */ COUNT } protected final Query<T> queryToAggregate; private final AggregateFunction function; public AggregateQuery(AggregateFunction function, Query<T> queryToAggregate) { this.function = function; this.queryToAggregate = queryToAggregate; } @Override public void where(Expression expr) { queryToAggregate.where(expr); } @Override public void sort(Key<?> key, SortDirection direction) { queryToAggregate.sort(key, direction); } @Override public void limit(int n) { queryToAggregate.limit(n); } @Override public Expression getWhereExpression() { return queryToAggregate.getWhereExpression(); } /** * * @return The function by which to aggregate by. */ public AggregateFunction getAggregateFunction() { return this.function; } }