You could try the following.
I'd suggest that you make a copy of the SEPM DB to another new DB in the SQL Server instance, and try the query(ies) on the copy. NOT THE ORIGINAL DB.
To check that you have duplicate records in your table do the following:
select count(*) from TableName
and
select distinct * from TableName
You have duplicate records if the number of records returned by the second query,
is less than the number of records returned by the first.
you can do is to copy all the distinct records into a new table:
select distinct *
into DuplicateTable
from TableName
This query will create a new table (DuplicateTable) containing all the records in the original table but without any records being duplicated. It will preserve a single copy of those records which were duplicated.
This will only help you to identlfy the Duplicate Entries in the DB.
In order to delete the duplicates effectively, you'll need to run the following query:
delete * from table_name
This query will effectively remove all the entries in the specific identified table. Ideally in this scenario, the table name will be something like "clientname" or "client name". Be sure to lookup the table thru the SQL Explorer / SQL Server Management Tools before you run the query with the designated table name.
HTH.