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cChainedRelationBase.h

Go to the documentation of this file.

/******************************************************************************/
/*                                                                            */
/* POLiTe - Persistent Object Library Test                                    */
/*                                        Ph.D. Thesis by Mgr. Michal Kopecky */
/*                                                                            */
/* Charles University Prague                                                  */
/*                                                                            */
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/*                                                                            */
/* File name: ...                                                             */
/* Module: ......                                                             */
/*                                                                            */
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#ifndef __C_CHAINEDRELATIONBASE_H__
#define __C_CHAINEDRELATIONBASE_H__

// Parent Header(s)
#include <cRelation.h>

class DLL_External ChainedRelationBase : public Relation {
#ifdef POLITE_TEST_FRIEND
        friend POLITE_TEST_FRIEND;
#endif // POLITE_TEST_FRIEND

friend class QueRefProto;
friend class OneToOneRelationBase;
friend class OneToManyRelationBase;
friend class ManyToOneRelationBase;
friend class ManyToManyRelationBase;

protected:
        //Following attributes were added because of support of ChainedRelation, in other
        //types of relations they are not used:
        char *_inner_columns;
        //SQL fragment of joining columns "inside" ChainedRelation with aliases
        int _relnum;
        //Number of chained binary relations
        int _qnum;
        //Number of non-empty Queries inside the relation
        Query _left_query;
        Query _right_query;


protected:
        ChainedRelationBase(
                const char *a_left_class_name,
                const char *a_right_class_name,
                const char *a_table_name,
                class Connection *a_database_connection,
                const char *a_left_column_name,
                const char *a_right_column_name,
                const char *a_inner_columns,
                const int a_relnum,
                const int a_qnum,
                const class Query &a_left_query,
                const class Query &a_right_query
        );

        ChainedRelationBase(
                const ChainedRelationBase &X,
                const ChainedRelationBase &Y
        );

        ChainedRelationBase(
                ProtoBase &X,
                ProtoBase &Y
        );

public:
        ~ChainedRelationBase();
        //Destructor of ChainedRelation

        virtual bool InsertCouple(RefBase &left, RefBase &right) {return false;};
        //Inserts a couple <L, R> to the OMT-relation.

        virtual bool DeleteCouple(RefBase &left, RefBase &right) {return false;};
        //Deletes a couple <L, R> from the OMT-relation.

        virtual bool LDeleteAll(class RefBase &right) {return false;};
        //Deletes all couples <X, right>

        virtual bool RDeleteAll(class RefBase &left) {return false;};
        //Deletes all couples <left, X>

        virtual bool WriteDDL(ofstream &S, class Database &Db);
        // generates DDL stements nedded for the library to run

protected:
        virtual class ResultBase *_LGetAll(
                ResultBase *rb,
                const class RefBase &right,
                const class QueRefProto &query = ALL
                );
        //Gets all objects connected to object "right"
        //according to "query"

        virtual ResultBase *_RGetAll(
                ResultBase *rb,
                const class RefBase &left,
                const class QueRefProto &query = ALL
                );
        //Gets all objects connected to object "left"
        //according to "query"

public:
        virtual bool ExistsCouple(
                const class RefBase &left,
                const class RefBase &right
        );
        //Tests if exists relation between the given objects

        ChainedRelationBase(const ChainedRelationBase &R);
        //Deep copy-constructor

/*
        ChainedRelation operator *(const QueRefProto &const Q) const;
        //ChainedRelation = Relation * QueRefProto

        ChainedRelation operator *(const ChainedRelation &const R) const;
        //Binds together two ChainedRelations

        ChainedRelation operator &(const class Relation &const R) const;
        //Intersection of relations

        ChainedRelation operator |(const class Relation &const R) const;
        //Union of relations

        ChainedRelation operator -(const class Relation &const R) const;
        //Substraction of relations
*/

protected:
        //Re-initialisation of the relation
        void _Init(
                const char *a_left_class_name,
                const char *a_right_class_name,
                const char *a_table_name,
                class Connection *a_database_connection,
                const char *a_left_column_name,
                const char *a_right_column_name,
                const char *a_inner_columns,
                const int a_relnum,
                const int a_qnum,
                const class Query &a_left_query,
                const class Query &a_right_query
                );

        virtual ResultBase *_LGetAll(
                ResultBase * rb,
                const class QueRefProto &qL,
                const class QueRefProto &qR
                );
        //Gets all objects on the left side fulfilling query qL connected to object
        //on the right fulfilling query qR

        virtual ResultBase *_RGetAll(
                ResultBase * rb,
                const class QueRefProto &qL,
                const class QueRefProto &qR
                );
        //Gets all objects on the right side fulfilling query qR connected to object
        //on the left fulfilling query qL

};

#endif //__C_CHAINEDRELATIONBASE_H__

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