如何使用SqlBulkCopy防止重复插入？

Question

I am going to use SqlBulkCopy, but I need to prevent duplicates insert. What is the best way to do it? Have I do check existence for each item before make execute WriteToServer command?

Answer 1

The best way to do this would be to add a unique index onto the table you are inserting the data into. This will prevent any duplicate entries from being added to the table.

This also prevents you from having to potentially load too much data into memory and creating other problems for yourself.

Answer 2

you do not really specify what is your source. If it is a flat file you could SqlBulkCopy into a staging table and afterwards use a insert into sql statement that filters out the duplicates.