/*
* 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.entity.EntityItem;
import com.caucho.amber.manager.AmberConnection;
import com.caucho.amber.query.FromItem;
import com.caucho.amber.query.QueryParseException;
import com.caucho.amber.query.QueryParser;
import com.caucho.amber.type.StringType;
import com.caucho.amber.type.AmberType;
import com.caucho.util.CharBuffer;
import com.caucho.util.L10N;
import java.sql.ResultSet;
import java.sql.SQLException;
/**
* Represents an Amber query expression
*/
abstract public class AbstractAmberExpr implements AmberExpr {
private static final L10N L = new L10N(AbstractAmberExpr.class);
/**
* Returns true for a boolean expression.
*/
public boolean isBoolean()
{
return false;
}
/**
* Returns the expr type.
*/
public AmberType getType()
{
return StringType.create();
}
/**
* Returns true if this expr has any relationship.
*/
public boolean hasRelationship()
{
return false;
}
/**
* Converts to a boolean expression.
*/
public AmberExpr createBoolean()
throws QueryParseException
{
if (isBoolean())
return this;
else
throw new QueryParseException(L.l("'{0}' can't be used as a boolean",
this));
}
/**
* Binds the expression as a select item.
*/
abstract public AmberExpr bindSelect(QueryParser parser);
/**
* Returns true if the expression uses the from item.
*/
public boolean usesFrom(FromItem from, int type)
{
return usesFrom(from, type, false);
}
/**
* Returns true if the expression uses the from item.
*/
public boolean usesFrom(FromItem from, int type, boolean isNot)
{
return false;
}
/**
* Returns true if the expression must exist
*/
public boolean exists(FromItem from)
{
return false;
}
/**
* Returns true if the expression must exist
*/
public boolean exists()
{
return false;
}
/**
* Returns true if the expression uses the from item.
*/
public AmberExpr replaceJoin(JoinExpr join)
{
return this;
}
/**
* Returns the number of columns.
*/
public int getColumnCount()
{
return 1;
}
/**
* Generates the where expression.
*/
public void generateWhere(CharBuffer cb)
{
throw new UnsupportedOperationException(getClass().getName());
}
/**
* Generates the (update) where expression.
*/
public void generateUpdateWhere(CharBuffer cb)
{
generateWhere(cb);
}
/**
* Generates the having expression.
*/
public void generateHaving(CharBuffer cb)
{
generateWhere(cb);
}
/**
* Generates the where in a join expression.
*/
public void generateJoin(CharBuffer cb)
{
generateWhere(cb);
}
/**
* Generates the select expression.
*/
public void generateSelect(CharBuffer cb)
{
generateWhere(cb);
}
/**
* Returns the object for the expr.
*/
public Object getObject(AmberConnection aConn, ResultSet rs, int index)
throws SQLException
{
return getType().getObject(aConn, rs, index);
}
/**
* Returns the object for the expr.
*/
public Object getCacheObject(AmberConnection aConn,
ResultSet rs, int index)
throws SQLException
{
return getObject(aConn, rs, index);
}
/**
* Returns the object for the expr.
*/
public EntityItem findItem(AmberConnection aConn, ResultSet rs, int index)
throws SQLException
{
return getType().findItem(aConn, rs, index);
}
/**
* Binds the argument type based on another expr.
*/
public void setInternalArgType(AmberExpr other)
{
if ((this instanceof ArgExpr) &&
(other instanceof AbstractAmberExpr)) {
ArgExpr arg = (ArgExpr) this;
arg.setType(((AbstractAmberExpr) other).getType());
}
}
}