Unresolved externals

[MarkoSan]

Hello again!

Once I want to compile I get following errors:

File cdatabaseconnection.h:

#ifndef CDATABASECONNECTION_H
#define CDATABASECONNECTION_H
 
// qt headers
#include <QObject>
#include <QSqlDatabase>
 
// c++ stl headers
#include <memory>
 
class CDatabaseConnection : public QSqlDatabase
{
        //Q_OBJECT
 
public:
        //CDatabaseConnection(QObject *parent);
        static std::auto_ptr<CDatabaseConnection>& Instance(QObject *parent);
        ~CDatabaseConnection();
 
private:
        static std::auto_ptr<CDatabaseConnection> m_pInstance;
};
 
//typedef std::auto_ptr<CDatabaseConnection> pdbType;
 
#endif // CDATABASECONNECTION_H

#ifndef CDATABASECONNECTION_H
#define CDATABASECONNECTION_H

// qt headers
#include <QObject>
#include <QSqlDatabase>

// c++ stl headers
#include <memory>

class CDatabaseConnection : public QSqlDatabase
{
        //Q_OBJECT

public:
        //CDatabaseConnection(QObject *parent);
        static std::auto_ptr<CDatabaseConnection>& Instance(QObject *parent);
        ~CDatabaseConnection();
 
private:
        static std::auto_ptr<CDatabaseConnection> m_pInstance;
};

//typedef std::auto_ptr<CDatabaseConnection> pdbType;

#endif // CDATABASECONNECTION_H

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File cdatabaseconnection.cpp:

#include "cdatabaseconnection.h"
 
/*
CDatabaseConnection::CDatabaseConnection(QObject *parent)
        : QSqlDatabase()
{
}
*/
 
CDatabaseConnection::~CDatabaseConnection()
{
}
 
std::auto_ptr<CDatabaseConnection>& CDatabaseConnection::Instance(QObject *parent)
{
        return m_pInstance;
}

#include "cdatabaseconnection.h"

/*
CDatabaseConnection::CDatabaseConnection(QObject *parent)
        : QSqlDatabase()
{
}
*/

CDatabaseConnection::~CDatabaseConnection()
{
}

std::auto_ptr<CDatabaseConnection>& CDatabaseConnection::Instance(QObject *parent)
{
        return m_pInstance;
}

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After compilation, I get linker errors:

Error 1 error LNK2001: unresolved external symbol "private: static class std::auto_ptr<class CDatabaseConnection> CDatabaseConnection::m_pInstance" (?m_pInstance@CDatabaseConnection@@0V?$auto_ptr@VC DatabaseConnection@@@std@@A) cdatabaseconnection.obj
Error 2 fatal error LNK1120: 1 unresolved externals C:\Documents and Settings\markofr.NESRAMNIK\Desktop\QBlagajna\Debug \QKlient.exe

Can someone help me please?