/*
* 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 SoftwareFoundation, Inc.
* 59 Temple Place, Suite 330
* Boston, MA 02111-1307 USA
*
* @author Scott Ferguson
*/
package com.caucho.db.sql;
import com.caucho.db.table.Column;
import com.caucho.db.table.Table;
import com.caucho.db.table.TableIterator;
import com.caucho.util.L10N;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.logging.Logger;
abstract class AbstractIdExpr extends Expr {
private static final L10N L = new L10N(IdExpr.class);
abstract protected FromItem getFromItem();
abstract protected Column getColumn();
abstract protected int getTableIndex();
public Class getType()
{
return getColumn().getJavaType();
}
/**
* Returns any column name.
*/
public String getName()
{
return getColumn().getName();
}
/**
* Returns the column's table.
*/
public Table getTable()
{
return getFromItem().getTable();
}
/**
* Returns true if the column can contain a null value.
*/
@Override
public boolean isNullable()
{
return ! getColumn().isNotNull();
}
/**
* The cost of a match of the expr.
*/
protected long lookupCost(ArrayList<FromItem> fromList)
{
final FromItem fromItem = getFromItem();
if (! fromList.contains(fromItem))
return COST_NO_TABLE;
if (fromList.indexOf(fromItem) < fromList.size() - 1)
return 0;
final Column column = getColumn();
if (column.isPrimaryKey())
return COST_INDEX;
else if (column.isUnique())
return COST_UNIQUE;
else
return COST_SCAN;
}
/**
* The cost of a match of the expr.
*/
@Override
public long subCost(ArrayList<FromItem> fromList)
{
if (! fromList.contains(getFromItem()))
return Integer.MAX_VALUE;
return 10 * 100 * 100 * 100;
}
@Override
public Expr bind(Query query)
throws SQLException
{
return this;
}
/**
* Returns true if the expression is null.
*/
@Override
public boolean isNull(final QueryContext context)
throws SQLException
{
final TableIterator []rows = context.getTableIterators();
final TableIterator row = rows[getTableIndex()];
return row.isNull(getColumn());
}
/**
* Evaluates the expression as a string.
*/
public String evalString(final QueryContext context)
throws SQLException
{
final TableIterator []rows = context.getTableIterators();
final TableIterator row = rows[getTableIndex()];
return row.getString(getColumn());
}
/**
* Evaluates the expression as a boolean.
*/
public int evalBoolean(final QueryContext context)
throws SQLException
{
final TableIterator []rows = context.getTableIterators();
final TableIterator row = rows[getTableIndex()];
final String value = row.getString(getColumn());
if (value == null)
return UNKNOWN;
else if (value.equals("1"))
return TRUE;
else if (value.equalsIgnoreCase("t"))
return TRUE;
else if (value.equalsIgnoreCase("y"))
return TRUE;
else
return FALSE;
}
public int evalInt(final QueryContext context)
throws SQLException
{
final TableIterator []rows = context.getTableIterators();
final TableIterator row = rows[getTableIndex()];
return row.getInteger(getColumn());
}
@Override
public long evalLong(final QueryContext context)
throws SQLException
{
final TableIterator []rows = context.getTableIterators();
final TableIterator row = rows[getTableIndex()];
return row.getLong(getColumn());
}
@Override
public double evalDouble(final QueryContext context)
throws SQLException
{
final TableIterator []rows = context.getTableIterators();
final TableIterator row = rows[getTableIndex()];
return row.getDouble(getColumn());
}
/**
* Evaluates the expression, writing to the result stream.
*
* @param context the query context
* @param result the output result
*/
@Override
public void evalToResult(final QueryContext context,
final SelectResult result)
throws SQLException
{
final TableIterator []rows = context.getTableIterators();
final TableIterator row = rows[getTableIndex()];
row.evalToResult(getColumn(), result);
}
/**
* Evaluates the expression to a buffer
*
* @param result the result buffer
*
* @return the length of the result
*/
@Override
public int evalToBuffer(QueryContext context,
byte []buffer,
int offset)
throws SQLException
{
TableIterator []rows = context.getTableIterators();
TableIterator row = rows[getTableIndex()];
return row.getBuffer(getColumn(), buffer, offset);
}
public boolean evalEqual(QueryContext context, byte []matchBuffer)
throws SQLException
{
TableIterator []rows = context.getTableIterators();
TableIterator row = rows[getTableIndex()];
return row.isEqual(getColumn(), matchBuffer);
}
public boolean evalEqual(QueryContext context, String string)
throws SQLException
{
TableIterator []rows = context.getTableIterators();
TableIterator row = rows[getTableIndex()];
return row.isEqual(getColumn(), string);
}
public boolean equals(Object o)
{
if (o == null || ! getClass().equals(o.getClass()))
return false;
AbstractIdExpr expr = (AbstractIdExpr) o;
return (getFromItem() == expr.getFromItem()
&& getColumn() == expr.getColumn());
}
public String toString()
{
return getFromItem().getName() + "." + getColumn().getName();
}
}