Excel Import - synchronization

Hi All, I am trying to import a excel sheet using Excel Importer module. In this table, there is no ideal candidate to be unique as a primary key so i tried the following to maintain a key.(needed for synchronization) 1.An autonumber attribute as a key which shows with log message “ successfully uploaded” but nothing gets imported to mendix application. 2.An integer attribute which is updated with an autonumber value in the change activity , here that integer column need to be filled manually otherwise excel sheet will not get uploaded with the null exception.Manual seeding of that column is not a better option since many users are involved. 3.Using String with two attributes concatenated together as a key, here records are getting uploaded but if again same records are uploaded it creates new objects  which results in duplicate entries. Let me know your inputs for handling this issue. My idea is to avoid duplicate entries even though multiple users are uploading the records. Thanks in advance
1 answers

Upload the data in a temporary table, then process the data into the operational table.

Then you have the option to create the key from different fields and use this to retrieve the record with this key from the operational table and if not found create the record, else update the record.

To completely make sure that ther are no concurrency issues you’ll need to process the records in the order thay come in, for that the process queue module from the appstore might be useful.