Import and prevent duplication

[Nick]

I import data from a disk daily and sometimes I have to
import an updated version of information for the same
date in the afternoon. I currently delete the morning
data and import the afternoon updated version. Is there
away to import without duplicating the information or
have to go through the delete process.

 

[martin]

I do something similar in another application. I load
the "new" data into another table with the exact structure
of the main table. Then I use an update query to match
the records between the two tables and update the main
table with the new data. The only thing I had to do was
to make sure I could create a key that is unique enough to
distinguish one record from another. In one instance, I
had to concantenate several fields together to do this.

Hope this helps.