SQL Security :: File Size And Space Used Is Not Displaying For All Database Other Than Master

I executed the below query and getting the capacity values only for master database.All other DB shows NULL values for spaceused. I'm actually looking for a query to get all the capacity information other than using temp table and the procedures. Is there any way using SQL query ONLY.

select
db.[dbid] as 'DB ID',
db.[name] as 'Database Name',
af.[name] as 'Logical Name',
convert(decimal(12,2),round(size/128.000,2)) as FileSizeMB, 
convert(decimal(12,2),round(fileproperty(db.name,'SpaceUsed')/128.000,2)) as SpaceUsedMB
from sys.sysdatabases db
inner join sys.sysaltfiles af
on db.dbid = af.dbid

Below is the output

DB ID Database Name
Logical Name FileSizeMB
SpaceUsedMB
1 master
master 4.00
3.44
1 master
mastlog 2.00

[Code] ....