Write data from csv to Postgres using Python and overwrite existing rows

Question

I am currently exporting a csv file to a Postgres database, however if I do this operation multiple times, the same rows happen to be duplicated in the database.

How can I modify my code to overwrite existing rows to avoid duplication?

with open('file1.csv', 'r') as f:
    next(f)
    cur.copy_from(f, 'table1', sep=',')
            
conn.commit()

Answer 1

You cannot do that with COPY .

You could use INSERT... ON CONFLICT , but that necessitates that you create a unique constraint or index that defines what you mean by "duplicate".