You can import data to update existing parent records, update child records and add child records. For example, you want to update a primary address field and add a secondary address to the record. You must import data to update the parent record and add the secondary address as a new child record.
Before you import data to update parent records, add the row ID primary key or the source key in the source file. To update child records, add the parent row ID, child row ID or the child cross reference primary key in the source file. To update cross reference records, add the cross reference primary key in the source file.
When you import a file to update records using the source key and the source system, you must enter a value in all required fields. If you do not enter a value in the required fields, an error displays.