question

I am using the below code to check the fragmentation percentage of one of my database to which my query editor points to SELECT OBJECT_NAME(ind.OBJECT_ID) AS TableName, ind.name AS IndexName, ips.index_type_desc AS IndexType, ips.avg_fragmentation_in_percent FROM sys.dm_db_index_physical_stats(DB_ID(), NULL, NULL, NULL, 'LIMITED') ips INNER JOIN sys.indexes ind ON ind.object_id = ips.object_id AND ind.index_id = ips.index_id WHERE ips.avg_fragmentation_in_percent > 20 I get the error as "Incorrect syntax near (" when I compile/execute the query. The problem seems to be when I mention DB_ID(). If I mention NULL or the database ID explicitly. there is no problem. -- This code works fine SELECT OBJECT_NAME(ind.OBJECT_ID) AS TableName, ind.name AS IndexName, ips.index_type_desc AS IndexType, ips.avg_fragmentation_in_percent FROM sys.dm_db_index_physical_stats(16, NULL, NULL, NULL, 'LIMITED') ips INNER JOIN sys.indexes ind ON ind.object_id = ips.object_id AND ind.index_id = ips.index_id WHERE ips.avg_fragmentation_in_percent > 20 -- Similarly this too works fine SELECT OBJECT_NAME(ind.OBJECT_ID) AS TableName, ind.name AS IndexName, ips.index_type_desc AS IndexType, ips.avg_fragmentation_in_percent FROM sys.dm_db_index_physical_stats(NULL, NULL, NULL, NULL, 'LIMITED') ips INNER JOIN sys.indexes ind ON ind.object_id = ips.object_id AND ind.index_id = ips.index_id WHERE ips.avg_fragmentation_in_percent > 20 I know the query is valid, and it does not show problems when I run the same query on a separate database instance on the same server (and on system databases as well). I want to know why the behavior is such when I mention DB_ID() in the query?