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Resin Java Application Server
/*
* Copyright (c) 1998-2012 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 SoftwareFoundation, Inc.
* 59 Temple Place, Suite 330
* Boston, MA 02111-1307 USA
*
* @author Scott Ferguson
*/
package com.caucho.db.sql;
import java.sql.Blob;
import java.sql.SQLException;
import java.util.ArrayList;
import com.caucho.db.table.Column.ColumnType;
import com.caucho.inject.Module;
@Module
final class EqExpr extends Expr {
private final Expr _left;
private final Expr _right;
EqExpr(Expr left, Expr right)
{
if (left == null || right == null)
throw new NullPointerException();
if (right instanceof UnboundIdentifierExpr
&& ! (left instanceof UnboundIdentifierExpr)) {
Expr temp = right;
right = left;
left = temp;
}
_left = left;
_right = right;
}
@Override
public Expr bind(Query query)
throws SQLException
{
Expr newLeft = _left.bind(query);
Expr newRight = _right.bind(query);
if (newLeft instanceof ColumnExpr
&& newLeft.getType().equals(String.class)) {
return new StringEqExpr((ColumnExpr) newLeft, newRight);
}
else if (newRight instanceof ColumnExpr
&& newRight.getType().equals(String.class)) {
return new StringEqExpr((ColumnExpr) newRight, newLeft);
}
if ((newLeft instanceof ColumnExpr || newLeft instanceof IdExpr)
&& newLeft.getTypeCode() == ColumnType.BINARY) {
return new BinaryColumnEqExpr(newLeft, newRight);
}
else if ((newRight instanceof ColumnExpr || newRight instanceof IdExpr)
&& newRight.getTypeCode() == ColumnType.BINARY) {
return new BinaryColumnEqExpr(newRight, newLeft);
}
if (newLeft.isLong() && (newRight.isLong() || newRight.isParam()))
return new LongEqExpr(newLeft, newRight);
else if (newRight.isLong() && (newLeft.isLong() || newLeft.isParam()))
return new LongEqExpr(newLeft, newRight);
if (newLeft.isDouble() && (newRight.isDouble() || newRight.isParam()))
return new DoubleEqExpr(newLeft, newRight);
if (newRight.isDouble() && (newLeft.isDouble() || newLeft.isParam()))
return new DoubleEqExpr(newLeft, newRight);
if (_left == newLeft && _right == newRight)
return this;
else
return new EqExpr(newLeft, newRight);
}
/**
* Returns an index expression if available.
*/
@Override
public RowIterateExpr getIndexExpr(FromItem item)
{
if (_left instanceof IdExpr) {
IdExpr expr = (IdExpr) _left;
if (item != expr.getFromItem()) {
}
else if (expr.getColumn().getTypeCode() == ColumnType.IDENTITY) {
return new IdentityIndexExpr(expr, _right);
}
else if (expr.getColumn().getIndex() != null) {
return new IndexExpr(expr, _right);
}
}
else if (_left instanceof OidExpr) {
OidExpr expr = (OidExpr) _left;
if (item == expr.getFromItem()) {
return new OidIndexExpr(expr, _right);
}
}
if (_right instanceof IdExpr) {
IdExpr expr = (IdExpr) _right;
if (item != expr.getFromItem()) {
}
else if (expr.getColumn().getTypeCode() == ColumnType.IDENTITY) {
return new IdentityIndexExpr(expr, _left);
}
else if (expr.getColumn().getIndex() != null) {
return new IndexExpr(expr, _left);
}
}
else if (_right instanceof OidExpr) {
OidExpr expr = (OidExpr) _right;
if (item == expr.getFromItem()) {
return new OidIndexExpr(expr, _left);
}
}
return null;
}
/**
* Returns the type of the expression.
*/
@Override
public Class getType()
{
return boolean.class;
}
/**
* Returns the cost based on the given FromList.
*/
@Override
public long cost(ArrayList fromList)
{
if (_left instanceof UnboundIdentifierExpr
&& _right.cost(fromList) == 0) {
UnboundIdentifierExpr id = (UnboundIdentifierExpr) _left;
return id.lookupCost(fromList);
}
else if (_right instanceof UnboundIdentifierExpr
&& _left.cost(fromList) == 0) {
UnboundIdentifierExpr id = (UnboundIdentifierExpr) _right;
return id.lookupCost(fromList);
}
else {
return subCost(fromList);
}
}
/**
* Returns the cost based on a subitem.
*/
@Override
public long subCost(ArrayList fromList)
{
return _left.subCost(fromList) + _right.subCost(fromList);
}
/**
* Returns the cost based on the given FromList.
*/
@Override
public long indexCost(ArrayList costItems)
{
long leftCost = _left.indexSubCost(costItems);
long rightCost = _right.indexSubCost(costItems);
if (leftCost < rightCost)
return leftCost;
else
return rightCost;
}
/**
* Evaluates the expression for nulls
*/
@Override
public boolean isNull(QueryContext context)
throws SQLException
{
return (_left.isNull(context) || _right.isNull(context));
}
/**
* Evaluates the expression as a boolean.
*/
@Override
public int evalBoolean(QueryContext context)
throws SQLException
{
if (_left.isNull(context) || _right.isNull(context))
return UNKNOWN;
if (_left.isLong() && _right.isLong()) {
if (_left.evalLong(context) == _right.evalLong(context))
return TRUE;
else
return FALSE;
}
else if (_left.isDouble() && _right.isDouble()) {
if (_left.evalDouble(context) == _right.evalDouble(context))
return TRUE;
else
return FALSE;
}
else {
String leftValue = _left.evalString(context);
String rightValue = _right.evalString(context);
if (leftValue == rightValue || leftValue.equals(rightValue))
return TRUE;
else
return FALSE;
}
}
@Override
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
*/
@Override
public void evalGroup(QueryContext context)
throws SQLException
{
_left.evalGroup(context);
_right.evalGroup(context);
}
public String toString()
{
return "(" + _left + " = " + _right + ")";
}
}