How To Compare Across Two Databases

I have two databases - version 1 and version 2

I have the same table in both versions but the number of columns has changed from version 1 to version 2.

I can get the list of columns with:
select colid, name, col_text from _SCHEMA
where table_name like
'tableA' order by colid

How can I use something like this to compare tableA in dbo.1 to tableA in dbo.2 and just return the columns that exist in dbo.2 that aren't in dbo.1?

I thought something like this might do it, but I get major errors in execution:
use dbo.2 select colid, name, col_text from _SCHEMA
where table_name like
'tableA' and
name not in (use dbo.1 select name from _SCHEMA
where table_name like
'tableA')
order by colid