Find Tables Without Primary Keys

SELECT Schema_name(o.schema_id) AS [schema],

       Object_name(i.object_id) AS [table],

       p.ROWS,

       user_seeks,

       user_scans,

       user_lookups,

       user_updates,

       last_user_seek,

       last_user_scan,

       last_user_lookup

FROM   sys.indexes i

       INNER JOIN sys.objects o

         ON i.object_id = o.object_id

       INNER JOIN sys.partitions p

         ON i.object_id = p.object_id

            AND i.index_id = p.index_id

       LEFT OUTER JOIN sys.dm_db_index_usage_stats ius

         ON i.object_id = ius.object_id

            AND i.index_id = ius.index_id

WHERE  i.type_desc = 'HEAP'

ORDER  BY ROWS DESC