Number of Rows and Data and Indexes Space Used Per Table

This query is extracted from the Disk Usage by Top Table report in SQL Server Management Studio.

SELECT
		[a3].[name] AS [schemaname], [a2].[name] AS [tablename], [a1].[rows] AS [row_count],
		( [a1].[reserved] + ISNULL ([a4].[reserved], 0)) * 8 AS [reserved],
		[a1].[data] * 8 AS [data],
		( CASE
			WHEN ( [a1].[used] + ISNULL ([a4].[used], 0)) > [a1].[data] THEN
		( [a1].[used] + ISNULL ([a4].[used], 0)) - [a1].[data]
			ELSE
				0
		END ) * 8 AS [index_size],
		( CASE
			WHEN ( [a1].[reserved] + ISNULL ([a4].[reserved], 0)) > [a1].[used] THEN
		( [a1].[reserved] + ISNULL ([a4].[reserved], 0)) - [a1].[used]
			ELSE
				0
		END ) * 8 AS [unused]
FROM	(	SELECT	[ps].[object_id],
					SUM (CASE WHEN ( [ps].[index_id] < 2 ) THEN	[ps].[row_count] ELSE 0	END) AS [rows],
					SUM ([ps].[reserved_page_count]) AS [reserved],
					SUM (
						CASE
							WHEN ( [ps].[index_id] < 2 ) THEN
						( [ps].[in_row_data_page_count] + [ps].[lob_used_page_count] + [ps].[row_overflow_used_page_count] )
							ELSE
						( [ps].[lob_used_page_count] + [ps].[row_overflow_used_page_count] )
						END) AS [data],
					SUM ([ps].[used_page_count]) AS [used]
			FROM	[sys].[dm_db_partition_stats] [ps]
			WHERE [ps].[object_id] NOT IN ( SELECT [object_id] FROM	[sys].[tables] WHERE [is_memory_optimized] = 1 )
			GROUP BY [ps].[object_id] ) AS [a1]
	LEFT OUTER JOIN ( SELECT	[it].[parent_id], SUM ([ps].[reserved_page_count]) AS [reserved], SUM ([ps].[used_page_count]) AS [used]
					  FROM	[sys].[dm_db_partition_stats] [ps]
							INNER JOIN [sys].[internal_tables] [it] ON ( [it].[object_id] = [ps].[object_id] )
					  WHERE [it].[internal_type] IN ( 202, 204 )
					  GROUP BY [it].[parent_id] ) AS [a4] ON ( [a4].[parent_id] = [a1].[object_id] )
	INNER JOIN [sys].[all_objects] [a2] ON ( [a1].[object_id] = [a2].[object_id] )
	INNER JOIN [sys].[schemas] [a3] ON ( [a2].[schema_id] = [a3].[schema_id] )
WHERE [a2].[type] <> N'S' AND [a2].[type] <> N'IT'
ORDER BY schemaname, tablename