You can use our Create Records in Bulk from CSV Fileautomation for this. It processes CSV files stored in attachment fields (e.g. uploaded through a form or portal) and will generate and/or update records in a target table based on the data within. It functions in a similar way as our regular CSV Importer automation, but with CSV files sourced from an attachment field, instead of a link.
The Unique ID Field Name (for Upsert) setting is required, as it is crucial in identifying existing records. Without it, the automation would have no way of knowing which record to update with what data.
Setup
Create or choose a source table where people will upload CSV files. Add an attachment field for those files. Prepare a separate target table with the fields that should receive the imported data.
Give the CSV a header row whose column names match the target Airtable field names. Include a unique ID column with a stable value for each row, and create a matching field in the target table.
Create the Create Records in Bulk from CSV File automation and select the source table, not the target table, as the main Table.
Under Setup, choose the CSV Attachment Field containing uploaded CSV files, then set Target Table to the table that should receive the rows.
Enter the exact target field name in Unique ID Field Name (for Upsert). The CSV must contain a column with this same name. A matching ID updates the existing record; a new ID creates a record.
Upload a small CSV to one test source record and run the automation for that record. Check both new and updated target records before allowing larger uploads.
Only the first attachment in each source record is processed. Upload a valid CSV file as that first attachment. Empty CSV cells do not clear an existing target value; they are omitted from the update.