/Users/green/Documents/workspace/DavisDB_public/IQueryOperator.h

/*
 *  IQueryOperator.h
 *  DavisDB
 *
 *  Created by Todd J. Green on 5/6/10.
 *  Copyright 2010 University of California, Davis. All rights reserved.
 *
 */

#ifndef _IQUERYOPERATOR_H
#define _IQUERYOPERATOR_H

#include "Common.h"
#include "Record.h"
#include "SystemManager.h"
#include "SystemPrinter.h"

#define CASE(x) case x: printf(#x); break;

#define TO_STRING(op) \
{\
switch(op) {\
CASE(EQ_OP)\
CASE(LT_OP)\
CASE(GT_OP)\
CASE(LE_OP)\
CASE(GE_OP)\
CASE(NE_OP)\
CASE(NO_OP)\
}\
}

class IQueryOperator {
public:
        virtual ReturnCode openExecution() = 0;
        
        virtual ReturnCode closeExecution() = 0;
        
        virtual ReturnCode getNextRecord(Record* record) = 0;
        
        virtual int getArity() = 0;
        
        virtual void getSchema(RelationAttributeInfo attributes[]) = 0;
        
        virtual void printSubtree(int indent) = 0;
        
        virtual ~IQueryOperator() {};
};

#endif // _IQUERYOPERATOR_H

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