If a foreign key referenced only one of the rows you are deleting, isn't that by definition not a duplicate? So then in that case can't you just delete with the unique key?
He is saying if the table has a primary key and many columns but the data is already screwed up. Now they identify four other columns combination as unique but data shows duplicates by these four. (The four columns should have had a design of unique key to begin with)
Jason
http://dbace.us
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