Latest backup size - max(backup_finish_date)

Question

Why does this query return multiple rows per database?
select database_name, backup_size, max(backup_finish_date)
from msdb.dbo.backupset
where database_name = 'Ditest' and type='D'
group by database_name, backup_size
order by backup_finish_date desc
SQL Server 2008r2, enterprise edition
Dianne

Answer 1

Hmm, ROW_NUMBER() was introduced in SQL Server 2005, so as long as it's not SQL 2000, the above query should work fine. Otherwise there are other ways to get the top row and as I said, if you're looking for particular database, then just use top 1 query.
If you want this to work for all DBs, then check Tibor's query.
You can also see these blogs 
http://social.technet.microsoft.com/wiki/contents/articles/19670.t-sql-useful-links.aspx#Select_Top_N_Rows_per_Group
and pick up any of other solutions from these blogs that work in lower versions of SQL Server.
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