I use sqlitebrowser (GUI) to read the contents of the LXD database file.
Indeed, making changes with any external tool may mess up LXD in unexpected ways.
Here is sqlitebrowser. I have selected a table, and then I can use the Up/Down arrow keys to easily navigate through all the tables in the database. I can see the columns and also the data. For the purposes of learning what’s in the database, I think it’s really useful.
