You can edit a database if you want to change the name, layout or add, edit or delete columns.
Click on "Databases" in the left menu.
Click on "Settings".
Choose the database you want to edit.
From here you can edit Columns, Settings and Layout.
In Columns you can add a new field by simple drag and drop it in the listed order.
A column can be edited by clicking on the pencil or deleted by clicking on the red trashcan.
Notice: If you delete a column all data in the column will be deleted.
In settings you can edit the name and icon.
In layout you can change which column to be displayed in a relation, list or dropdown layout.