Every day, I migrate data from a MySQL database to BigQuery. For most processes, I use LoadJobConfig().writedisposition with WRITE_APPEND. However, for my raw_stock table, using WRITE_APPEND doesn’t work because I need to update the existing data instead.

I have a local file in .csv format with a header, containing only the rows that need updating. They are identified by id_store and id_product (which form a composite primary key). The columns to be updated are product_amount and date_update.

The entire process is done through Python. The necessary libraries and credentials are already set up.

My attempts resulted in either deleting and replacing the data or adding new rows. I specifically need the updates and nothing else. I tried searching for information in the documentation provided by GCP but was unsuccessful in finding the correct answer.

I’m still a novice in this area and unsure how to handle the updates. Could someone please help me out?

Thank you in advance.