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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.SQLException;
import java.util.ArrayList;
import com.caucho.db.table.Column;
import com.caucho.db.table.Table;
import com.caucho.db.table.TableIterator;
import com.caucho.db.table.Column.ColumnType;
import com.caucho.db.xa.DbTransaction;
final class IdExpr extends Expr {
private final FromItem _fromItem;
private final Column _column;
private int _tableIndex = -1;
/**
* Creates an unbound identifier with just a column name.
*/
IdExpr(FromItem fromItem, Column column)
{
_fromItem = fromItem;
_column = column;
}
@Override
public Class getType()
{
return _column.getJavaType();
}
/**
* Returns the column.
*/
public Column getColumn()
{
return _column;
}
@Override
public ColumnType getTypeCode()
{
return getColumn().getTypeCode();
}
/**
* Returns any column name.
*/
@Override
public String getName()
{
return _column.getName();
}
/**
* Returns the from item
*/
public FromItem getFromItem()
{
return _fromItem;
}
/**
* Returns the column's table.
*/
@Override
public Table getTable()
{
return _fromItem.getTable();
}
/**
* Returns true if the column can contain a null value.
*/
@Override
public boolean isNullable()
{
return ! _column.isNotNull();
}
/**
* The cost of a match of the expr.
*/
protected long lookupCost(ArrayList fromList)
{
if (! fromList.contains(_fromItem))
return COST_NO_TABLE;
if (fromList.indexOf(_fromItem) < fromList.size() - 1)
return 0;
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 fromList)
{
if (! fromList.contains(_fromItem)) {
return Integer.MAX_VALUE;
}
return 10 * 100 * 100 * 100;
}
@Override
public long indexSubCost(ArrayList costItems)
{
if (_column.getIndex() != null && ! costItems.contains(_fromItem))
return INDEX_COST_INDEX;
else
return COST_INVALID;
}
@Override
public Expr bind(Query query)
throws SQLException
{
FromItem []fromItems = query.getFromItems();
for (int i = 0; i < fromItems.length; i++) {
if (fromItems[i] == _fromItem)
_tableIndex = i;
}
return this;
}
/**
* Returns true if the expression is null.
*/
@Override
public boolean isNull(QueryContext context)
throws SQLException
{
TableIterator []rows = context.getTableIterators();
TableIterator row = rows[_tableIndex];
return row.isNull(_column);
}
/**
* Evaluates the expression as a string.
*/
@Override
public String evalString(QueryContext context)
throws SQLException
{
TableIterator []rows = context.getTableIterators();
TableIterator row = rows[_tableIndex];
return row.getString(_column);
}
/**
* Update the expression as a string.
*/
@Override
public void updateString(QueryContext context, String value)
throws SQLException
{
DbTransaction xa = context.getTransaction();
TableIterator []rows = context.getTableIterators();
TableIterator row = rows[_tableIndex];
row.setString(xa, _column, value);
}
/**
* Evaluates the expression as a boolean.
*/
@Override
public int evalBoolean(QueryContext context)
throws SQLException
{
TableIterator []rows = context.getTableIterators();
TableIterator row = rows[_tableIndex];
String value = row.getString(_column);
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(QueryContext context)
throws SQLException
{
TableIterator []rows = context.getTableIterators();
TableIterator row = rows[_tableIndex];
return row.getInteger(_column);
}
@Override
public long evalLong(QueryContext context)
throws SQLException
{
TableIterator []rows = context.getTableIterators();
TableIterator row = rows[_tableIndex];
return row.getLong(_column);
}
/**
* Update the expression as a string.
*/
@Override
public void updateLong(QueryContext context, long value)
throws SQLException
{
DbTransaction xa = context.getTransaction();
TableIterator []rows = context.getTableIterators();
TableIterator row = rows[_tableIndex];
row.setLong(xa, _column, value);
}
@Override
public double evalDouble(QueryContext context)
throws SQLException
{
TableIterator []rows = context.getTableIterators();
TableIterator row = rows[_tableIndex];
return row.getDouble(_column);
}
/**
* Update the expression as a string.
*/
@Override
public void updateDouble(QueryContext context, double value)
throws SQLException
{
DbTransaction xa = context.getTransaction();
TableIterator []rows = context.getTableIterators();
TableIterator row = rows[_tableIndex];
row.setDouble(xa, _column, value);
}
/**
* Evaluates the expression as a string.
*/
@Override
public byte []evalBytes(QueryContext context)
throws SQLException
{
TableIterator []rows = context.getTableIterators();
TableIterator row = rows[_tableIndex];
return row.getBytes(_column);
}
/**
* Evaluates the expression, writing to the result stream.
*
* @param context the query context
* @param result the output result
*/
@Override
public void evalToResult(QueryContext context, SelectResult result)
throws SQLException
{
TableIterator []rows = context.getTableIterators();
TableIterator row = rows[_tableIndex];
row.evalToResult(_column, 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[_tableIndex];
return row.getBuffer(_column, buffer, offset);
}
public boolean evalEqual(QueryContext context, byte []matchBuffer)
throws SQLException
{
TableIterator []rows = context.getTableIterators();
TableIterator row = rows[_tableIndex];
return row.isEqual(_column, matchBuffer);
}
@Override
public boolean evalEqual(QueryContext context, String string)
throws SQLException
{
TableIterator []rows = context.getTableIterators();
TableIterator row = rows[_tableIndex];
return row.isEqual(_column, string);
}
@Override
public boolean equals(Object o)
{
if (o == null || ! IdExpr.class.equals(o.getClass()))
return false;
IdExpr expr = (IdExpr) o;
return (_fromItem == expr._fromItem &&
_column == expr._column);
}
public String toString()
{
return _fromItem.getName() + "." + _column.getName();
}
}