Autonumber

An autonumber field automatically generates a unique and automatically incremented number for each record.Autonumber field is very helpful when you need to use a unique identifier to mark each record.

Please note that when a record is deleted, the remaining records are not re-numbered.

For example: when I have three records that are identified with autonumber 1, 2, 3, if I delete the 3rd record and then add another record, the new record will be identified with autonumber 4 rather than 3.

If you'd like to re-number your records, you can delete and then re-create an autonumber field, or convert the field to a different type and then change back to the autonumber type.