/*
 * Hibernate, Relational Persistence for Idiomatic Java
 *
 * Copyright (c) 2010, Red Hat Inc. or third-party contributors as
 * indicated by the @author tags or express copyright attribution
 * statements applied by the authors.  All third-party contributions are
 * distributed under license by Red Hat Inc.
 *
 * This copyrighted material is made available to anyone wishing to use, modify,
 * copy, or redistribute it subject to the terms and conditions of the GNU
 * Lesser General Public License, as published by the Free Software Foundation.
 *
 * This program 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 distribution; if not, write to:
 * Free Software Foundation, Inc.
 * 51 Franklin Street, Fifth Floor
 * Boston, MA  02110-1301  USA
 */
package org.hibernate.dialect.function;

import java.sql.Types;

Some databases strictly return the type of the of the aggregation value for AVG which is
problematic in the case of averaging integers because the decimals will be dropped.  The usual workaround
is to cast the integer argument as some form of double/decimal.
Author:
Steve Ebersole/**
 * Some databases strictly return the type of the of the aggregation value for <tt>AVG</tt> which is
 * problematic in the case of averaging integers because the decimals will be dropped.  The usual workaround
 * is to cast the integer argument as some form of double/decimal.
 *
 * @author Steve Ebersole
 */
public class AvgWithArgumentCastFunction extends StandardAnsiSqlAggregationFunctions.AvgFunction {
	private final String castType;

	
Constructs a AvgWithArgumentCastFunction
Params:
castType – The type to cast the avg argument to/**
	 * Constructs a AvgWithArgumentCastFunction
	 *
	 * @param castType The type to cast the avg argument to
	 */
	public AvgWithArgumentCastFunction(String castType) {
		this.castType = castType;
	}

	@Override
	protected String renderArgument(String argument, int firstArgumentJdbcType) {
		if ( firstArgumentJdbcType == Types.DOUBLE || firstArgumentJdbcType == Types.FLOAT ) {
			return argument;
		}
		else {
			return "cast(" + argument + " as " + castType + ")";
		}
	}
}