/*
* Copyright (C) 2000 - 2008 TagServlet Ltd
*
* This file is part of Open BlueDragon (OpenBD) CFML Server Engine.
*
* OpenBD is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* Free Software Foundation,version 3.
*
* OpenBD 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. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with OpenBD. If not, see http://www.gnu.org/licenses/
*
* Additional permission under GNU GPL version 3 section 7
*
* If you modify this Program, or any covered work, by linking or combining
* it with any of the JARS listed in the README.txt (or a modified version of
* (that library), containing parts covered by the terms of that JAR, the
* licensors of this Program grant you additional permission to convey the
* resulting work.
* README.txt @ http://www.openbluedragon.org/license/README.txt
*
* http://www.openbluedragon.org/
*/
package com.naryx.tagfusion.cfm.queryofqueries;
/**
* This class represents the count function.
* On each call to the evaluate function the count function
* will update the result taking into account all the rowContexts
* it has witnessed so far.
* It will maintain the reference to the same instance that it
* returned as the result therefore it is important that the
* result returned is not altered.
*/
import java.util.List;
import com.naryx.tagfusion.cfm.engine.cfData;
import com.naryx.tagfusion.cfm.engine.cfNumberData;
public class countFunction extends aggregateFunction {
expression expr; // countParam
cfNumberData count;
countFunction(){
// * ASTERISK
count = new cfNumberData( 0.0 );
}// countFunction()
countFunction( expression _e ){
this();
expr = _e;
}// countFunction()
public cfData evaluate( rowContext _rowContext, List<cfData> _preparedData ){
count.add( 1.0 );
return count;
}// evaluate()
public void reset(){
count.set( 0.0 );
}// reset()
expression copy(){
countFunction copy = new countFunction();
copy.expr = expr;
return copy;
}// copy()
public String toString(){
return "COUNT ( " + ( expr == null ? "*" : expr.toString() ) + " )";
}// toString()
} // countFunction