All SQL tables generated by SQList contain Author and Editor columns, which represent the user who created and last modified the item. However, these columns do not contain usernames but rather user IDs.
It is possible to export the User Information List, that contains all user details and can be joined to the IDs in the Author and Editor columns, from the site collection's root website using a Site Collection Administrator account.
All users and groups that have access to a SharePoint sites in a site collection are held in the User Information List. This list is not site specific and is only found at the root of the site collection.
Furthermore, only users that have Site Collection Administrator privileges can read and export this list. In all other ways, the User Information List can be exported using SQList like any other list.
Note: the User Information List" is named differently depending on the language; e.g. "Elenco Informazioni Utente" in Italian.