Database: cre_Doc_and_collections
Question: List subset id, name and number of different documents in each subset.
SQL:
SELECT T1.Document_Subset_ID ,  T2.Document_Subset_Name , count(DISTINCT T1.Document_Object_ID) FROM Document_Subset_Members AS T1 JOIN Document_Subsets AS T2 ON T1.Document_Subset_ID =  T2.Document_Subset_ID GROUP BY T1.Document_Subset_ID;