values in the AutoNumber field are not sequential, why?

  • Thread starter Thread starter jeffhill
  • Start date Start date
J

jeffhill

While entering records into database, I entered the same record two times. I
deleted the record with the duplicate information and then added a new
record. Now the values in the AutoNumber field are not sequential. How can
this be?
 
At the first data entry keystroke of a new record, Access assigns the
autonumber which is the highest existing autonumber +1. Access never goes
back and trys to assign a missing autonumber. When you delete a record,
Access deletes the assigned autonumber and that number is gone forever never
to be reused.

Steve
(e-mail address removed)
 
While entering records into database, I entered the same record two times. I
deleted the record with the duplicate information and then added a new
record. Now the values in the AutoNumber field are not sequential. How can
this be?
Click to expand...

That's the way AutoNumbers work. Once a number is assigned to a new
record, if you delete that record that number is not re-used. Even
without deleting a record, AutoNumbers are only required to be unique,
not sequential, and gaps can occur.
If, for some reason, you need to have a sequential number, you'll have
to create your own system. But again, once you delete a record, let's
say record #54 out of a sequence of 1 to 100, you will still have a
missing number.
 
In addition to what everyone else has told you, why does it matter?

The only reason for an AutoNumber field is to provide a (practically
guaranteed) unique value that can be used as a primary key. 231, 233, 234
serves that need just as well as 1, 2, 3. If the value of the AutoNumber
field matters to you, you probably shouldn't be using an AutoNumber field.
 
Auto numbers are meant to increment, but not necessarily are
sequential.
Click to expand...

Long integer Autonumbers can be sequential or random. They are
sequential by default. They can also be "ReplicationID" instead of
long integer, in which case they are neither sequential nor random.
 
Back
Top