Primary Key columns in CRM

I developed the following query today to examine the primary key columns in tables in CRM.  I hope this helps you in some way.

select distinct a.name as KeyColumn, b.name as TableName

from metadataschema.attribute a

inner join metadataschema.entity b

on a.entityid = b.entityid

where a.ispkattribute = 1

order by b.name