SQL Server 2008: How to query all databases sizes?

Question

I have MS SQL 2008 R2, 500 databases. What is the most efficient, easiest and \'modern\' way to query all databases sizes.

The output should have columns:

Answer 1

sometimes SECURITY issues prevent from asking for all the db's and you need to query one by one with the db prefix, for those cases i created this dynamic query

go
declare @Results table ([Name] nvarchar(max), [DataFileSizeMB] int, [LogFileSizeMB] int);

declare @QaQuery nvarchar(max)
declare @name nvarchar(max)

declare MY_CURSOR cursor 
  local static read_only forward_only
for 
select name from master.dbo.sysdatabases where name not in ('master', 'tempdb', 'model', 'msdb', 'rdsadmin');

open MY_CURSOR
fetch next from MY_CURSOR into @name
while @@FETCH_STATUS = 0
begin 
    if(len(@name)>0)
    begin
        print @name + ' Column Exist'
        set @QaQuery = N'select 
                            '''+@name+''' as Name
                            ,sum(case when type = 0 then size else 0 end) as DataFileSizeMB
                            ,sum(case when type = 1 then size else 0 end) as LogFileSizeMB
                        from ['+@name+'].sys.database_files
                        group by replace(name, ''_log'', '''')';

        insert @Results exec sp_executesql @QaQuery;
    end
  fetch next from MY_CURSOR into @name
end
close MY_CURSOR
deallocate MY_CURSOR

select * from @Results order by DataFileSizeMB desc
go