How to handle this duplicate data

Hi,
I am conver Flatfile into database( mean: store tha flatfile data into database) but how to handle douplicate records.
I run the program twotimes same data store into the database repeatedly, how to handle this duplicate data store into DB.

ename id sal
Ram 1001 7000
Pavan 1002 6000
Ram 1001 7000
Pavan 1002 6000

HOW TO HANDLE THIS DUPLICATE DATA

can U PLZ give any one Idea…:sad: