Getting a "type" column from each table in query
Perhaps this is what you are looking for:

(SELECT id, name, 'Book' AS media_type
FROM books
LIMIT 0,3) 

UNION ALL 

(SELECT id, name, 'Video' AS media_type
FROM videos
LIMIT 0,3)

UNION ALL

(SELECT id, name, 'Album' AS media_type
FROM albums
LIMIT 0,3);


I don't know if you need any particular ordering or not.  According to the docs, UNION produces an unordered set of rows.  You should be able to add an ORDER BY after the last SELECT, outside the parentheses.