Finding Unique Table/Column Combinations Across SQL Databases

I have 4 databases with similar schema's, and I'm trying to create a query to return just the table, column pairs that exist ONLY in database 1 and do not exist in database 2, 3, or 4.

Currently I can return the symmetric difference between database 1 and 2 via the following query...

select table_name, column_name from (
     select table_name, column_name from [Database1].information_schema.columns
     union all
     select table_name, column_name from [Database2].information_schema.columns) as tmp
     group by table_name, column_name having count(*) = 1

However, in trying to isolate just those columns in database 1, and doing the same across all 4 databases, things are getting complicated. What is the cleanest solution for this query?

From stackoverflow

• SELECT
       D1.table_name,
       D1.column_name
  FROM
       Database1.information_schema.columns D1
  LEFT OUTER JOIN Database2.information_schema.columns D2 ON
       D2.table_name = D1.table_name AND
       D2.column_name = D1.column_name
  LEFT OUTER JOIN Database3.information_schema.columns D3 ON
       D3.table_name = D1.table_name AND
       D3.column_name = D1.column_name
  LEFT OUTER JOIN Database4.information_schema.columns D4 ON
       D4.table_name = D1.table_name AND
       D4.column_name = D1.column_name
  WHERE
       D2.table_name IS NULL AND
       D3.table_name IS NULL AND
       D4.table_name IS NULL
  

  Blorgbeard : you have a trailing AND

  Tom H. : Thanks. I need to work on my copy-paste skills :)

• I can come up with this at first shot, which can be a head start. This hasn't been tested though, just another alternative maybe:

  select table_name, column_name from [Database1].information_schema.columns d1 where table_name || '+' || column_name not in (select table_name || '+' || column_name from [Database2].information_schema.columns)

  and table_name || '+' || column_name not in (select table_name || '+' || column_name from [Database3].information_schema.columns)

  and table_name || '+' || column_name not in (select table_name || '+' || column_name from [Database4].information_schema.columns)