/*
* 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.expression;
import org.castor.cpa.persistence.sql.query.Qualifier;
import org.castor.cpa.persistence.sql.query.QueryConstants;
import org.castor.cpa.persistence.sql.query.Visitor;
/**
* Class representing a column of the database table.
*
* @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: 2006-04-25 15:08:23 -0600 (Tue, 25 Apr 2006) $
*/
public final class Column extends Expression {
//-----------------------------------------------------------------------------------
/** Qualifier the column belongs to. May be <code>null</code> if there is no risk
* for name clashes for a SQL query. */
private final Qualifier _qualifier;
/** Name of the column. */
private final String _name;
//-----------------------------------------------------------------------------------
/**
* Construct a column that has no qualifier with given name.
*
* @param name Name of the column.
*/
public Column(final String name) {
this(null, name);
}
/**
* Construct a column with given qualifier and name.
*
* @param qualifier Qualifier the column belongs to.
* @param name Name of the column.
*/
public Column(final Qualifier qualifier, final String name) {
if (name == null) { throw new NullPointerException(); }
_qualifier = qualifier;
_name = name;
}
//-----------------------------------------------------------------------------------
/**
* Returns qualifier the column belongs to.
*
* @return Qualifier the column belongs to.
*/
public Qualifier qualifier() {
return _qualifier;
}
/**
* Returns name of the column.
*
* @return Name of the column.
*/
public String name() {
return _name;
}
//-----------------------------------------------------------------------------------
/**
* {@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();
if (_qualifier != null) {
sb.append(_qualifier.toString());
sb.append(QueryConstants.DOT);
}
sb.append(_name);
return sb.toString();
}
//-----------------------------------------------------------------------------------
}