Page Splits on an empty table
if DB_ID(N'DB_NAME') returns null you will get object_id's from all databases.  Try running from the target database:

use db_name


SELECT IOS.index_id, 
       O.NAME                       AS OBJECT_NAME, 
       I.NAME                       AS INDEX_NAME, 
       IOS.leaf_allocation_count    AS PAGE_SPLIT_FOR_INDEX, 
       IOS.nonleaf_allocation_count PAGE_ALLOCATION_CAUSED_BY_PAGESPLIT 
FROM 
sys.dm_db_index_operational_stats(Db_id(), NULL, NULL, NULL) IOS
JOIN sys.indexes I 
  ON IOS.index_id = I.index_id 
     AND IOS.object_id = I.object_id 
JOIN sys.objects O 
  ON IOS.object_id = O.object_id 
WHERE  o.NAME NOT LIKE 'sys%' 
       AND i.NAME IS NOT NULL 
       AND IOS.leaf_allocation_count != 0 
       AND IOS.nonleaf_allocation_count != 0 
ORDER  BY IOS.leaf_allocation_count DESC