treatment of duplicate records by sqldataadapter

I use sqldataadapter to add several records to a database.  Some, but not all, of those records may already be included in the source table and may contravene the primary key or unique index.  It seems that when I call sqldataadapter.update it will insert all records until it hits the first duplicate and then insert no more valid (non-duplicate) trades after that point.  What I want it to do is insert all records but ignore, or skip over, the duplicates.  What is the best way for me to achieve this.

Thanks