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cRelation.h

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

#ifndef __C_RELATION_H__
#define __C_RELATION_H__

// Standard Header(s)
#include <fstream.h>

// Common POLiTe Header(s)
#include <lStr.h>

// Other POLiTe Header(s)
#include <cQuery.h>

template<class L,class R> class ChainedRelation;

class DLL_External Relation {
#ifdef POLITE_TEST_FRIEND
        friend POLITE_TEST_FRIEND;
#endif // POLITE_TEST_FRIEND

friend ChainedRelationBase;

protected:
        //Identification of the database where related instances are stored.
        class Connection *_databaseConnection;
        //Each relation knows class names of both its sides,
        //a table it corresponds to and names of key columns
        const char *_leftClassName;
        char *_leftColumnName;
        const char *_rightClassName;
        char *_tableName;
        char *_rightColumnName;

public:
        Relation(
                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 = NULL,
                const char *a_right_column_name = NULL
                );

        virtual ~Relation();

        Relation &Connection(class Connection *DbConn) {_databaseConnection=DbConn; return *this;};

        virtual bool InsertCouple(class RefBase &left, class RefBase &right) = 0;
        virtual bool InsertCouple(class Object &left, class RefBase &right);
        virtual bool InsertCouple(class RefBase &left, class Object &right);
        virtual bool InsertCouple(class Object &left, class Object &right);
        //Inserts a couple <L, R> to the OMT-relation.

        virtual bool DeleteCouple(RefBase &left, RefBase &right) = 0;
        virtual bool DeleteCouple(class Object &left, class RefBase &right);
        virtual bool DeleteCouple(class RefBase &left, class Object &right);
        virtual bool DeleteCouple(class Object &left, class Object &right);
        //Deletes a couple <L, R> from the OMT-relation.

        virtual bool LDeleteAll(class RefBase &right) = 0;
        virtual bool LDeleteAll(class Object &right);
        //Deletes all couples <X, right>
        virtual bool DeleteLeft(class RefBase &right) {return LDeleteAll(right);};
        virtual bool DeleteLeft(class Object &right) {return LDeleteAll(right);};
        //The same as LDeleteAll

        virtual bool RDeleteAll(class RefBase &left) = 0;
        virtual bool RDeleteAll(class Object &left);
        //Deletes all couples <left, X>
        virtual bool DeleteRight(class RefBase &left) {return RDeleteAll(left);};
        virtual bool DeleteRight(class Object &left) {return RDeleteAll(left);};
        //The same as RDeleteAll

protected:
        virtual class ResultBase *_LGetAll(
                ResultBase *rb,
                const class RefBase &right,
                const class QueRefProto &query = EQUERY
                ) = 0;
        //Gets all objects connected to object "right"
        //according to "query"

        virtual ResultBase *_RGetAll(
                ResultBase *rb,
                const class RefBase &left,
                const class QueRefProto &query = EQUERY
                ) = 0;
        //Gets all objects connected to object "left"
        //according to "query"

public:
        virtual bool WriteDDL(ofstream &S, class Database &Db) = 0;
        // generates DDL stements nedded for the library to run

        virtual bool LExists(const class RefBase &right, const class QueRefProto &query = EQUERY);
        virtual bool LExists(const class Object &right, const class QueRefProto &query = EQUERY);
        //Tests if exists any object connected to object "right"
        //according to "query"

        virtual bool RExists(const class RefBase &left, const class QueRefProto &query = EQUERY);
        virtual bool RExists(const class Object &left, const class QueRefProto &query = EQUERY);
        //Tests if exists any object connected to object "left"
        //according to "query"

        virtual bool ExistsCouple(const class RefBase &left,const class RefBase &right) = 0;
        virtual bool ExistsCouple(const class Object &left,const class RefBase &right);
        virtual bool ExistsCouple(const class RefBase &left,const class Object &right);
        virtual bool ExistsCouple(const class Object &left,const class Object &right);
        //Tests if exists relation between the given objects

protected:
        virtual const char *_TableName() const {return _tableName;};
        // Returns a table name, where both sets of foreign keys are
        // it is NOT a _table_name column for all types of relations!

        virtual ResultBase *_LGetAll(
                ResultBase * rb,
                const class QueRefProto &qL,
                const class QueRefProto &qR
                ) = 0;
        //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
                ) = 0;
        //Gets all objects on the right side fulfilling query qR connected to object
        //on the left fulfilling query qL
};

#endif //__C_RELATION_H__

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