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select 'matched to ', t.pk, d.*
from Table as D
inner Join Table as T
on D.Pk < T.PK
and D.Firstname=T.FirstName
and D.Lastname=T.lastName
you need criteria to decide which one to delete
Delete from Table
Where Exists (Select T.pk from table as T
Where T.pk > Table.pk
and T.firstname=Table.firstnam
and t.lastname = table.lastname)
I hope this isn't HOMEWORK ?