保存数据库调用的合理方法是什么？

I´m working on a PHP-Codeigniter Page that uses a MySQL Database.

On this page Users can login with their Google-OpenID and save some file-upload "Projects".

class Entry
{
    private $mEntID;
    private $mCatID;
    private $mName;
    private $mDescription;
    private $mUserID;
    private $mMainThumb;
}


class User
{
    private $mUserID;   
    private $mIdentityURL;
    private $mFirstname;
    private $mLastname;
    private $mEmail;
}

On some Pages I will show user-details of each Entry.

Which is the best way?

1. Do 2-Database-Calls and generate an Entry-Object with an User-Object inside
2. Save an serialized User-Object in the "Entries"-Tabel, by saving a new Entry-Project
3. Something else :)

The first solution needs more database-calls, but there are less updating-problems if user-details are changing, while the second solution probably has a better performance