/*
* 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.amber.expr;
import com.caucho.amber.query.FromItem;
import com.caucho.amber.query.QueryParseException;
import com.caucho.amber.query.QueryParser;
import com.caucho.amber.table.AmberColumn;
import com.caucho.amber.table.LinkColumns;
import com.caucho.amber.type.AmberType;
import com.caucho.util.CharBuffer;
/**
* Bound identifier expression.
*/
public class ColumnExpr extends AbstractAmberExpr {
protected PathExpr _parent;
// identifier name value
private AmberColumn _column;
protected FromItem _fromItem;
/**
* Creates a new unbound id expression.
*/
public ColumnExpr(PathExpr parent, AmberColumn column)
{
_parent = parent;
_column = column;
}
/**
* Returns the parent.
*/
public PathExpr getParent()
{
return _parent;
}
/**
* Returns the name.
*/
public AmberColumn getColumn()
{
return _column;
}
/**
* Returns the expr type.
*/
public AmberType getType()
{
return getColumn().getType();
}
/**
* Returns true if this expr has any relationship.
*/
public boolean hasRelationship()
{
// jpa/1232
return ! (_parent instanceof IdExpr);
}
/**
* Returns a boolean expression.
*/
public AmberExpr createBoolean()
throws QueryParseException
{
if (getColumn().getType().isBoolean())
return new BooleanColumnExpr(_parent, _column);
else
return super.createBoolean();
}
/**
* Binds the expression as a select item.
*/
public AmberExpr bindSelect(QueryParser parser)
{
FromItem parentFromItem = _parent.bindSubPath(parser);
if (parentFromItem.getTable() == getColumn().getTable()) {
_fromItem = parentFromItem;
return this;
}
LinkColumns link = getColumn().getTable().getDependentIdLink();
if (link == null)
return this;
_fromItem = parser.createDependentFromItem(parentFromItem, link);
return this;
}
/**
* Returns true if the expression uses the from item.
*/
public boolean usesFrom(FromItem from, int type, boolean isNot)
{
if (from.isOuterJoin() && type == AmberExpr.IS_INNER_JOIN) {
// jpa/115a
return false;
}
if (_fromItem == from)
return true;
else if (_fromItem == null && _parent.getChildFromItem() == from)
return true;
else
return false;
}
/**
* Replaces linked join to eliminate a table.
*/
public AmberExpr replaceJoin(JoinExpr join)
{
_parent = (PathExpr) _parent.replaceJoin(join);
return this;
}
/**
* Generates the where expression.
*/
public void generateWhere(CharBuffer cb)
{
generateInternalWhere(cb, true);
}
/**
* Generates the (update) where expression.
*/
public void generateUpdateWhere(CharBuffer cb)
{
generateInternalWhere(cb, false);
}
/**
* Generates the having expression.
*/
public void generateHaving(CharBuffer cb)
{
generateWhere(cb);
}
public String toString()
{
return _parent + "." + _column.getName();
}
//
// private
private void generateInternalWhere(CharBuffer cb,
boolean select)
{
if (_fromItem != null) {
if (select) {
cb.append(_fromItem.getName());
cb.append('.');
}
cb.append(_column.getName());
}
else {
if (select) {
cb.append(_parent.getChildFromItem().getName());
cb.append('.');
}
cb.append(_column.getName());
}
}
}