SQL Server query data size

SELECT db_name(database_id) as [Database Name],[Name]  as [Logical Name],[Physical_name]  as [Physical Name], ((Size* 8)/ 1024x768/1024x768) as [Size (GB)],[Differential_base_time]  as [differential Base time] fromSys.master_files

1 , query the remaining space for each disk partition:
Execmaster.dbo.xp_fixeddrives

2 , querying database data files and log files related information (including filegroup, current file size, file maximum, file growth settings, file logical name, file path, etc.)
select* from [database name]. [dbo]. [Sysfiles]
Convert file size in MB:
Selectname, CONVERT (float,size) * (8192.0/1024.0)/1024. From [Database name].dbo.sysfiles

3 , querying the disk usage of the current database:
Execsp_spaceused

4, query database server each database log file size and utilization
Dbccsqlperf (Logspace)

SQL Server query data size