/*
* Copyright (c) 1998-2011 Caucho Technology -- all rights reserved
*
* This file is part of Resin(R) Open Source
*
* Each copy or derived work must preserve the copyright notice and this
* notice unmodified.
*
* Resin Open Source 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 of the License, or
* (at your option) any later version.
*
* Resin Open Source 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, or any warranty
* of NON-INFRINGEMENT. See the GNU General Public License for more
* details.
*
* You should have received a copy of the GNU General Public License
* along with Resin Open Source; if not, write to the
*
* Free Software Foundation, Inc.
* 59 Temple Place, Suite 330
* Boston, MA 02111-1307 USA
*
* @author Scott Ferguson
*/
package com.caucho.db.sql;
import java.sql.SQLException;
import java.util.ArrayList;
class CmpExpr extends AbstractBinaryExpr {
private Expr _left;
private Expr _right;
private int _op;
CmpExpr(Expr left, Expr right, int op)
{
_left = left;
_right = right;
_op = op;
}
@Override
public final Expr getLeft()
{
return _left;
}
@Override
public final Expr getRight()
{
return _right;
}
@Override
public Expr create(Expr left, Expr right)
{
return new CmpExpr(left, right, _op);
}
public Expr bind(Query query)
throws SQLException
{
_left = _left.bind(query);
_right = _right.bind(query);
/*
if (_left.isLong() && _right.isLong())
return new LongCmpExpr(_op, _left, _right);
*/
switch (_op) {
case Parser.LT:
if (_left.isNullable() || _right.isNullable())
return new DoubleLtExpr(_left, _right);
else
return new DoubleLtNonNullExpr(_left, _right);
case Parser.LE:
if (_left.isNullable() || _right.isNullable()) {
return new DoubleLeExpr(_left, _right);
}
else
return new DoubleLeNonNullExpr(_left, _right);
case Parser.GT:
return new DoubleGtExpr(_left, _right);
case Parser.GE:
return new DoubleGeExpr(_left, _right);
}
if (_left.isDouble() || _right.isDouble()) {
switch (_op) {
case Parser.EQ:
return new DoubleEqExpr(_left, _right);
case Parser.NE:
return new DoubleNeqExpr(_left, _right);
}
}
return this;
}
/**
* Returns the type of the expression.
*/
public Class getType()
{
return boolean.class;
}
/**
* Returns the cost based on the given FromList.
*/
public long subCost(ArrayList<FromItem> fromList)
{
return _left.subCost(fromList) + _right.subCost(fromList);
}
/**
* Evaluates the expression as a boolean.
*/
public int evalBoolean(QueryContext context)
throws SQLException
{
if (_left.isNull(context) || _right.isNull(context))
return UNKNOWN;
switch (_op) {
case Parser.NE:
{
String leftValue = _left.evalString(context);
String rightValue = _right.evalString(context);
if (! (leftValue == rightValue
|| leftValue != null && leftValue.equals(rightValue)))
return TRUE;
else
return FALSE;
}
case Parser.EQ:
{
String leftValue = _left.evalString(context);
String rightValue = _right.evalString(context);
if (leftValue == rightValue
|| leftValue != null && leftValue.equals(rightValue))
return TRUE;
else
return FALSE;
}
default:
throw new SQLException("can't compare");
}
}
public String evalString(QueryContext context)
throws SQLException
{
throw new SQLException("can't convert string to boolean");
}
/**
* Evaluates aggregate functions during the group phase.
*
* @param state the current database tuple
*/
public void evalGroup(QueryContext context)
throws SQLException
{
_left.evalGroup(context);
_right.evalGroup(context);
}
public String toString()
{
switch (_op) {
case Parser.EQ:
return "(" + _left + " = " + _right + ")";
case Parser.NE:
return "(" + _left + " <> " + _right + ")";
case Parser.LT:
return "(" + _left + " < " + _right + ")";
case Parser.LE:
return "(" + _left + " <= " + _right + ")";
case Parser.GT:
return "(" + _left + " > " + _right + ")";
case Parser.GE:
return "(" + _left + " >= " + _right + ")";
default:
return "(" + _left + " =? " + _right + ")";
}
}
}