TOP query with multiple columns

You'll need a UNION query to produce a result set which contains all the values from each of the 4 columns in one result set column. Then you can do your "top N" query on the result set (which is called a derived table when used as a subquery).

Note that "top N" logic varies from one database to the next; see FIRST N rows, TOP N rows, LAST N rows, BOTTOM N rows...

Here's how it would look in SQL Server:

 select top 10 Topics, source, sourcevalue from ( select Topics , 'XX' as source, XX as sourcevalue from yourtable union all select Topics, 'YY', YY from yourtable union all select Topics, 'ZZ', ZZ from yourtable union all select Topics, 'RR', RR from yourtable ) as dt order by sourcevalue desc

Note UNION ALL instead of UNION, because we do not want the result set scanned for duplicates.