Finding duplicate rows in SQL Server

Question

I have a SQL Server database of organizations, and there are many duplicate rows. I want to run a select statement to grab all of these and the amount of dupes, but also return the ids that are associated with each organization.

A statement like:

SELECT     orgName, COUNT(*) AS dupes  
FROM         organizations  
GROUP BY orgName  
HAVING      (COUNT(*) > 1)

Will return something like

orgName        | dupes  
ABC Corp       | 7  
Foo Federation | 5  
Widget Company | 2 

But I'd also like to grab the IDs of them. Is there any way to do this? Maybe like a

orgName        | dupeCount | id  
ABC Corp       | 1         | 34  
ABC Corp       | 2         | 5  
...  
Widget Company | 1         | 10  
Widget Company | 2         | 2  

The reason being that there is also a separate table of users that link to these organizations, and I would like to unify them (therefore remove dupes so the users link to the same organization instead of dupe orgs). But I would like part manually so I don't screw anything up, but I would still need a statement returning the IDs of all the dupe orgs so I can go through the list of users.

Answer 1

select o.orgName, oc.dupeCount, o.id
from organizations o
inner join (
    SELECT orgName, COUNT(*) AS dupeCount
    FROM organizations
    GROUP BY orgName
    HAVING COUNT(*) > 1
) oc on o.orgName = oc.orgName