Listing 7: Abstract class for writing to a database

// Update.h:

#if !defined(UPDATE_H)
#define UPDATE_H

// All classes derived from class Update
// have protected ctors, and the associated
// business object class must be a friend,
// e.g., class Employee is a friend to class
// EmpUpdate (to allow an Employee object to
// instantiate an EmpUpdate object). This
// enforces the policy that updates can only
// be done through objects.

#include "DBXFace.h"

class Update : public DBXFace
{
public:
    BOOL write();
    virtual long getID() const = 0;

protected:
    Update(CRecordset*, Connection*);
    long nextID();
    virtual CString getIDTable() const = 0;

private:
    // Disallowed ops:
    Update(const Update&);
    void operator=(const Update&);
};

#endif

/* End of File */