lost value of object in c++ sqlite callback function - c++

Question

these are the functions, after building the correct object inside fillAlbum data gets lost in openAlbum.
/*
the function will fill the album with correct values (callback function)
*/
int fillAlbum(void* data, int argc, char** argv, char** azColName)
{
Album* album = new Album();
album->setName(argv[1]);
album->setCreationDate(argv[3]);
album->setOwner(std::stoi(argv[2]));
data = album;
return 0;
}
/*
the function return the asked album
*/
Album DatabaseAccess::openAlbum(const std::string& albumName)
{
Album album;
char** errMessage = nullptr;
std::string sqlStatement = "SELECT * FROM ALBUMS WHERE NAME LIKE '" + albumName + "';";
sqlite3_exec(db_access, sqlStatement.c_str(), fillAlbum, &album, errMessage);
return album;
}

Answer 1

It gets lost (in fact it is worse: you have a memory leak!) because you don't use the callback correctly. You pass &album and now you have to cast the void* pointer and fill it, not overwrite it (in fact, the data = album line has no effect at all outside the fillAlbum function, you just overwrite a local variable). Try this:
int fillAlbum(void* data, int argc, char** argv, char** azColName)
{
Album* album = static_cast<Album*>(data); // <-- this line is crucial
album->setName(argv[1]);
album->setCreationDate(argv[3]);
album->setOwner(std::stoi(argv[2]));
return 0;
}