Add special meta box to custom post type

I have managed to add a meta box to my custom post type (see code below)
Now I need to add another meta box. With this box I want to display / edit a value from another table called wp_project_bids_mitglied. This table contains a row with the post ids and a row with the values (0,1,2) that I would like to edit / display in my backend. How do I have to change the code to achieve this goal? Thanks!

Unable to save custom taxonomy terms in a custom-built metabox

I’ve roughly followed the tutorial here on how to create “custom taxonomy input panels”. I’m using a custom post type of homes and a custom taxonomy called beds (used to record the number of beds in a house). I’ve got the taxonomy terms showing up in a drop down menu, but cannot get them to save when the post is saved. I started to just post the code that is intended to save the term, but realized that I should post the code that creates and displays the metabox as well, for context. The custom post type name is ‘homes’ and the custom taxonomy name is ‘beds’. The taxonomy is hierarchical (not that I think that matters in this case, but I could be wrong).