/*
* JBoss, Home of Professional Open Source.
* See the COPYRIGHT.txt file distributed with this work for information
* regarding copyright ownership. Some portions may be licensed
* to Red Hat, Inc. under one or more contributor license agreements.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library 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 library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301 USA.
*/
package org.teiid.query.sql.lang;
import org.teiid.language.SortSpecification.NullOrdering;
import org.teiid.query.sql.LanguageObject;
import org.teiid.query.sql.LanguageVisitor;
import org.teiid.query.sql.symbol.Constant;
import org.teiid.query.sql.symbol.Expression;
import org.teiid.query.sql.symbol.ExpressionSymbol;
import org.teiid.query.sql.symbol.Symbol;
import org.teiid.query.sql.visitor.SQLStringVisitor;
public class OrderByItem implements LanguageObject {
private static final long serialVersionUID = 6937561370697819126L;
private Integer expressionPosition; //set during resolving to the select clause position
private boolean ascending = true;
private Expression symbol;
private NullOrdering nullOrdering;
public OrderByItem(Expression symbol, boolean ascending) {
setSymbol(symbol);
this.ascending = ascending;
}
public int getExpressionPosition() {
return expressionPosition == null?-1:expressionPosition;
}
public void setExpressionPosition(int expressionPosition) {
this.expressionPosition = expressionPosition;
}
public boolean isAscending() {
return ascending;
}
public void setAscending(boolean ascending) {
this.ascending = ascending;
}
public Expression getSymbol() {
return symbol;
}
public void setSymbol(Expression symbol) {
if (symbol != null && !(symbol instanceof Symbol) && !(symbol instanceof Constant)) {
symbol = new ExpressionSymbol("expr", symbol); //$NON-NLS-1$
}
this.symbol = symbol;
}
public NullOrdering getNullOrdering() {
return nullOrdering;
}
public void setNullOrdering(NullOrdering nullOrdering) {
this.nullOrdering = nullOrdering;
}
/**
*
* @return true if the expression does not appear in the select clause
*/
public boolean isUnrelated() {
return getExpressionPosition() == -1;
}
@Override
public void acceptVisitor(LanguageVisitor visitor) {
visitor.visit(this);
}
@Override
public OrderByItem clone() {
OrderByItem clone = new OrderByItem((Expression)this.symbol.clone(), ascending);
clone.expressionPosition = this.expressionPosition;
clone.nullOrdering = this.nullOrdering;
return clone;
}
@Override
public boolean equals(Object obj) {
if (obj == this) {
return true;
}
if (!(obj instanceof OrderByItem)) {
return false;
}
OrderByItem o = (OrderByItem)obj;
return o.symbol.equals(symbol) && o.ascending == this.ascending && o.nullOrdering == this.nullOrdering;
}
@Override
public int hashCode() {
return symbol.hashCode();
}
@Override
public String toString() {
return SQLStringVisitor.getSQLString(this);
}
}