lacasa
The use of Autonumber is to uniquely identify a record. One of the conditions for a good database and as part of "normalization" is that each record be uniquely identified.
The purpose of Autonumber is not to "count" records, or give an indication of the order records are created. The fact that the default setting for autonumber is to increment serially may be convenient, but should be treated as "cosmetic".
I can go on about this, but just consider these two points... a) Start creating a record, not the AutoNumber assigned (your ID number), and then cancel out without saving the record. Then create a new, and not that the next autonumber is now one higher. This is the way the system is designed. b) Imagine that you have to delete a lot of records. Say ID numbers 5 to 255 out of 100,000 records. Do want the "system" to now renumber all the other records from 256 to 100,000 to maintain the sequential sequence ... and renumber and related tables that use the ID as a foreign key?? The answer is NO.
So please don't be concerned about missing Autonumbers.
1 to 26, then it jumps to 1572878 ... Why the jump?
Very Good question. The next "Autonumber" is kept in one of the hidden system tables. You can get a large jump like this when developing a database, or running a large import and then, in either case, deleting the records. To jump by other 1.5 million is pretty wierd, and I suspect you did not delete that many records.
Another possibility is the randomization feature. By default, an Autnumber will use a sequential / incremental. Open your table in design mode and select the autonumbered field. Look at the bottom of the form at the "Field properties". Click on the field for "New values". From the drop down menu, you will see the other option is "random". Don't change the value from incremental, just yet.
A long interger (default value for AutoNumber) uses 4 bytes to accommodate a range of numbers from -2,147,483,648 to 2,147,483,647. Do you see a problem here? When using incremental or sequential numbers, you are loosing half of the available numbers as a long interger, specifically the negative numbers. However, since a long interger can go as high as 2.1 x 10^8 (2.1 billion for some, 2,100 million for others), the loss of half the available numbers is moot since a database of this size should be using Access.
Once you change a database from incremental -> random, you can not easily go back. However, I suspect, as long as none of the numbers are negative, I suspect the same method for resetting the Autonumber may be used for changing a random Autonumber fied -> incremental Autonumber field.
I suspect something like this may have happend to your database.
Remember when I said don't change the Autonumber from incremental to random at that time? I actually use the "random" number when using Autonumber - alot. But it will generate huge numbers, positive and negative. I am okay with this, and to avoid confusion on the end-user end, I hide the text box used to capture the Autonumber. Before doing anything like this though, back up your table.
Richard
