[pkscout]

By default, yes, all the play counts, watched statuses, resume points, and user Ratings would be lost.  You're basically starting with a brand new database.  I'm not sure if all those things are included if you export your library from Kodi, setup the new SQL db, and then import it.  Keep in mind that if you move to an SQL database and are sharing it between clients, the path to the video has to be valid and exactly the same for every device.  If you're also moving from local storage to, say, an SMB share, that will break everything if you try and export and then import.

[Karellen]

m not sure if all those things are included if you export your library from Kodi

They are.

But this user has a confusing situation. He does not want to use nfo files, wants to rescrape his library but wants selective scraping and preserve some info.
https://forum.kodi.tv/showthread.php?tid...pid3145663

Though it would be good if there was a comprehensive backup for "user created data" - Playcounts, last played, watched status, bookmarks. Interested?
WatchedList addon is no longer maintained, and does not backup user rating.

[pkscout]

But this user has a confusing situation. He does not want to use nfo files, wants to rescrape his library but wants selective scraping and preserve some info.
https://forum.kodi.tv/showthread.php?tid...pid3145663

I think I've about reached my limit on things I can maintain, especially one I'll never use.  It is an interesting challenge though, so maybe one day...

[Hrvoje]

By default, yes, all the play counts, watched statuses, resume points, and user Ratings would be lost.  You're basically starting with a brand new database.  I'm not sure if all those things are included if you export your library from Kodi, setup the new SQL db, and then import it.  Keep in mind that if you move to an SQL database and are sharing it between clients, the path to the video has to be valid and exactly the same for every device.  If you're also moving from local storage to, say, an SMB share, that will break everything if you try and export and then import.

Sorry, maybe my question wasn't properly written.Some time ago @Karellen  told me there is a bug when .nfo is used, and later migrated to SQL.Not sure if he meant on message only or in general how Kodi works?
https://forum.kodi.tv/showthread.php?tid...pid3079965

So the question is if I start from scratch(without using .nfo in any way), create new database on NAS, and then one day if I need to restore that new database would it work?Without need for various addons, .nfo files, etc...?

EDIT: I set the same path to NAS on all devices, and that part was fine.Everything was in sync.

In the last two years I partially lost data two times.
In short what I am looking for is proper way of backup Kodi data, and after restoration that everything would work.

[Hrvoje]

m not sure if all those things are included if you export your library from Kodi

They are.

But this user has a confusing situation. He does not want to use nfo files, wants to rescrape his library but wants selective scraping and preserve some info.
https://forum.kodi.tv/showthread.php?tid...pid3145663

Though it would be good if there was a comprehensive backup for "user created data" - Playcounts, last played, watched status, bookmarks. Interested?
WatchedList addon is no longer maintained, and does not backup user rating.

Actually restoring everything would be great, but if I remember correctly issue with using .nfo was with refreshing artwork, plot...When I did refresh user data was lost.And I think in some cases new videos were not recognized.Not sure what you meant with "selective scraping"?
For me important thing is user data like play counts, watched status, resume points and user Rating. 
Movie summary, actors, artwork etc would be nice, but if not possible I could probably live with that.

[pkscout]

By default, yes, all the play counts, watched statuses, resume points, and user Ratings would be lost.  You're basically starting with a brand new database.  I'm not sure if all those things are included if you export your library from Kodi, setup the new SQL db, and then import it.  Keep in mind that if you move to an SQL database and are sharing it between clients, the path to the video has to be valid and exactly the same for every device.  If you're also moving from local storage to, say, an SMB share, that will break everything if you try and export and then import.

Sorry, maybe my question wasn't properly written.Some time ago @Karellen  told me there is a bug when .nfo is used, and later migrated to SQL.Not sure if he meant on message only or in general how Kodi works?
https://forum.kodi.tv/showthread.php?tid...pid3079965

So the question is if I start from scratch(without using .nfo in any way), create new database on NAS, and then one day if I need to restore that new database would it work?Without need for various addons, .nfo files, etc...?

EDIT: I set the same path to NAS on all devices, and that part was fine.Everything was in sync.

In the last two years I partially lost data two times.
In short what I am looking for is proper way of backup Kodi data, and after restoration that everything would work.

To ensure you have a complete backup from which to recover, there are two things you should back up.  The Kodi database and the userdata folder on every client.  If you're using the built my database Kodi uses by default, that is stored in the userdata folder on each client.  So in that use case you only need to backup one thing - the userdata folder.  When you are using a MariaDB/MySQL backend, you also need to backup that database using whatever tool you want to back up the database.  Ditto for restores.

BTW, there is a Kodi addon to do backups:

https://kodi.wiki/view/Add-on:Backup

I think it's designed for the first case of using a local DB, but you could use it to backup everything else and then some other tool to backup your MySQL/MariaDB database.