cannot convert parameter 1 from 'char *' to 'long'

Ok, I switched to Visual C++ 2005 Express edition.

I have this code:

request.h

Code:

---

// Create prototype from Request class
class Request
{
      public:
            Request();
            ~Request();
           
            // Main function
            bool handle_requests();
           
            // MySQL Functions
            bool connect_to_db();
           
      protected:           
            // Winamp vars
            WINAMPCOMLib::IApplicationPtr winamp;
           
            // MySQL vars
            MYSQL * mysql_conn;
            MYSQL_RES * result;
            MYSQL_ROW row;
           
};

---

and main.cpp

Code:

---

#include <windows.h>
#include <mysql.h>
#include <iostream>
#include <stdio.h>

#import "c:\program files\winamp\plugins\gen_com.dll"
#include "request.h"

using namespace std;

Request::Request()
{
        // Create winamp instance
        Request::winamp.CreateInstance(__uuidof(WINAMPCOMLib::Application));                       
}
Request::~Request()
{
        mysql_close(Request::mysql_conn);
}

bool Request::connect_to_db()
{
        mysql_init(Request::mysql_conn);
        if(!mysql_real_connect(Request::mysql_conn, "localhost", "lucas", "***", "luckyradio", 0, NULL, 0))
        {
                cout << "Could not connect to database:\n" << mysql_error(Request::mysql_conn) << endl;
                return false;
        }
        return true;
}

bool Request::handle_requests()
{
        cout << "Started Winamp Request Handler" << endl;
        while(true)
        {
                if(!Request::winamp->CurrentPos)
                {
                        if(!mysql_query(Request::mysql_conn, "SELECT * FROM e107_wa_request ORDER BY request_id ASC LIMIT 1"))
                        {
                                cout << "Error in selecting requests:\n" << mysql_error(Request::mysql_conn) << endl;
                                return false;
                        }
                       
                        result = mysql_use_result(Request::mysql_conn);
                        row = mysql_fetch_row(result);
                       
                        Request::winamp->put_PlayListPos(row[1]);
                        Request::winamp->Play();
                       
                        cout << "Requesting: " << Request::winamp->GetSongTitle(row[1]) << "..." << endl;                                                 
                }
        }
       
        return false;
}

int main()
{
        Request request;
        if(request.connect_to_db())
        {
                while(request.handle_requests())
                {
                        // do nothing
                }
       
                cin.get();
        }
       
        return 1;
}

---

But I Get this error:

Quote:

---

------ Rebuild All started: Project: Requester, Configuration: Debug Win32 ------
Deleting intermediate and output files for project 'Requester', configuration 'Debug|Win32'
Compiling...
main.cpp
.\main.cpp(48) : error C2664: 'WINAMPCOMLib::IApplication::put_PlayListPos' : cannot convert parameter 1 from 'char *' to 'long'
There is no context in which this conversion is possible
.\main.cpp(51) : error C2664: 'WINAMPCOMLib::IApplication::GetSongTitle' : cannot convert parameter 1 from 'char *' to 'long'
There is no context in which this conversion is possible
Build log was saved at "file://c:\Documents and Settings\Lucas\My Documents\Visual Studio 2005\Projects\Requester\Requester\Debug\BuildLog.h tm"
Requester - 2 error(s), 0 warning(s)
========== Rebuild All: 0 succeeded, 1 failed, 0 skipped ==========

---

Does anyone know how I can fix this?

It appears that your functions are looking for long and not char*. If this a "work-around" for passing a pointer to the function then you will have to use reinterpret_cast<long>. I can only gues the function internal will cast it back to the pointer in order to use it.

something like this?

Code:

---

Request::winamp->put_PlayListPos(<long>row[1]);

---

?

Quote:

---

Originally Posted by MrLucky

something like this?

Code:

---

Request::winamp->put_PlayListPos(<long>row[1]);

---

?

---

You forgot the reinterpret_cast part. Like this.

Code:

---

Request::winamp->put_PlayListPos(reinterpret_cast<long>row[1]);

---

This will work as far as solving the "type" conflict, whether or not it works logical I do not know without knowing the underlying code.

I've got this now:

Code:

---

bool Request::handle_requests()
{
        cout << "Started Winamp Request Handler" << endl;
        while(true)
        {
                if(!Request::winamp->CurrentPos)
                {
                        if(!mysql_query(Request::mysql_conn, "SELECT * FROM e107_wa_request ORDER BY request_id ASC LIMIT 1"))
                        {
                                cout << "Error in selecting requests:\n" << mysql_error(Request::mysql_conn) << endl;
                                return false;
                        }
                       
                        result = mysql_use_result(Request::mysql_conn);
                        row = mysql_fetch_row(result);
                       
                        long playlist_pos = reinterpret_cast<long>(row[1]);
                       
                        Request::winamp->put_PlayListPos(playlist_pos);
                        Request::winamp->Play();
                       
                        cout << "Requesting: " << Request::winamp->GetSongTitle(playlist_pos) << "..." << endl;                                                 
                }
        }
       
        return false;
}

---

and this works :)

But now, I get some other errors..

Quote:

---

------ Build started: Project: Requester, Configuration: Debug Win32 ------
Compiling...
main.cpp
Linking...
main.obj : error LNK2019: unresolved external symbol _mysql_close@4 referenced in function "public: __thiscall Request::~Request(void)" (??1Request@@QAE@XZ)
main.obj : error LNK2019: unresolved external symbol _mysql_error@4 referenced in function "public: bool __thiscall Request::connect_to_db(void)" (?connect_to_db@Request@@QAE_NXZ)
main.obj : error LNK2019: unresolved external symbol _mysql_real_connect@32 referenced in function "public: bool __thiscall Request::connect_to_db(void)" (?connect_to_db@Request@@QAE_NXZ)
main.obj : error LNK2019: unresolved external symbol _mysql_init@4 referenced in function "public: bool __thiscall Request::connect_to_db(void)" (?connect_to_db@Request@@QAE_NXZ)
main.obj : error LNK2019: unresolved external symbol _mysql_fetch_row@4 referenced in function "public: bool __thiscall Request::handle_requests(void)" (?handle_requests@Request@@QAE_NXZ)
main.obj : error LNK2019: unresolved external symbol _mysql_use_result@4 referenced in function "public: bool __thiscall Request::handle_requests(void)" (?handle_requests@Request@@QAE_NXZ)
main.obj : error LNK2019: unresolved external symbol _mysql_query@8 referenced in function "public: bool __thiscall Request::handle_requests(void)" (?handle_requests@Request@@QAE_NXZ)
C:\Documents and Settings\Lucas\My Documents\Visual Studio 2005\Projects\Requester\Debug\Requester.exe : fatal error LNK1120: 7 unresolved externals
Build log was saved at "file://c:\Documents and Settings\Lucas\My Documents\Visual Studio 2005\Projects\Requester\Requester\Debug\BuildLog.h tm"
Requester - 8 error(s), 0 warning(s)
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========

---

I think I know how to fix this problem, just add the libmysql linker to my project. But does anyone know where I can add linkers to my project in Visual C++ 2005?

These are linker errors, have you inluded the mysql libraries in your project? With MSVC there are 2 ways you could do this. Easiest but non-portable is put this in your file: pragma comment (lib, "name_of_your_library"). The second way is to put it in the project linker properties in the "include additional libraries" option ( do it for both debug and release)

something like this?

Code:

---

#pragma "c:\mysql\lib\libmysqlclient.lib"

---

?

Edit
Already got it..