how to update table?

[Matt]

hi all,

i have a table in my database that needs to be updated every week with new
information. i import the new (updated) table into sql, then with to update
the new data into my existing table. Some data will be new entries, some
data will need to replace the old data.

what is the best way to do this?

i can manage to split my data into 2 if that helps:
1- new data
2- existing data to be replaced....

i am new so your help would be greatly appreciated!

thanks...