/*
* Copyright 2009 Ralf Joachim, Ahmad Hassan
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.castor.cpa.persistence.sql.query;
import org.castor.cpa.persistence.sql.query.expression.Column;
import org.castor.cpa.persistence.sql.query.expression.Expression;
/**
* Assignment used for SQL update statements.
*
* @author <a href="mailto:ahmad DOT hassan AT gmail DOT com">Ahmad Hassan</a>
* @author <a href="mailto:ralf DOT joachim AT syscon DOT eu">Ralf Joachim</a>
* @version $Revision$ $Date: 2009-07-13 17:22:43 (Mon, 13 Jul 2009) $
*/
public final class Assignment implements QueryObject {
//-----------------------------------------------------------------------------------
/** Left operand of the assignment. */
private final Column _left;
/** Right operand of the assignment. */
private final Expression _right;
//-----------------------------------------------------------------------------------
/**
* Constructor that assigns the given rigth hand operand cto the left hand one.
*
* @param left Left operand of the assignment.
* @param right Right operand of the assignment.
*/
public Assignment(final Column left, final Expression right) {
if ((left == null) || (right == null)) {
throw new NullPointerException();
}
_left = left;
_right = right;
}
//-----------------------------------------------------------------------------------
/**
* Returns left operand of the assignment.
*
* @return Left operand of the assignment.
*/
public Column leftExpression() {
return _left;
}
/**
* Returns right operand of the assignment.
*
* @return right operand of the assignment.
*/
public Expression rightExpression() {
return _right;
}
//-----------------------------------------------------------------------------------
/**
* {@inheritDoc}
*/
public void accept (final Visitor visitor) { visitor.visit(this); }
//-----------------------------------------------------------------------------------
/**
* Method constructing query string.
*
* @return Constructed query string.
*/
public String toString() {
StringBuffer sb = new StringBuffer();
sb.append(_left.toString());
sb.append(QueryConstants.ASSIGN);
sb.append(_right.toString());
return sb.toString();
}
//-----------------------------------------------------------------------------------
}