How to create an autonumber field in DAO?

I am creating a tabledef in code using DAO 3.5 and can not find the way to create an Autonumber field (Random).  When copying a current tabledef, the Autonumber field is picked up as a Long Integer (which is of course what it is.)  But what is the property setting? to make this field an Autonumber field?
Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

After setting up your field object you must set the Attributes property of that field object.

The following is the syntax to do this:

object.Attributes = dbAutoIncrField

See Vb's online documentation under Attributes for a comlete
bknouseAuthor Commented:
What about the RANDOM issue?
You can't make a "random" autonumber field.  Riffy was correct about how to make an auto increment field.  That's what an autonumber field is.  It increments.
The Ultimate Tool Kit for Technolgy Solution Provi

Broken down into practical pointers and step-by-step instructions, the IT Service Excellence Tool Kit delivers expert advice for technology solution providers. Get your free copy for valuable how-to assets including sample agreements, checklists, flowcharts, and more!

Auto Number or auto increment fields are always sequentially created numbers automatically generated by your database.  In order to generate these columns randomly, you must define them as a numeric type field, and calculate your own random numbers.  Generally, if you are considering an autonumber field for a primary key, I would advise against it.  Your best bet is to create an algorithm that recognizes some inherent randomness in your underlying data, and generate a unique number key using that randomness as a base.  The problem with sequential keys as primary keys is that most database systems try to colocate new rows on the same pages based upon primary keys.  In using an autonumber field as a primary key, you create a "hot spot" page for all new updates (and most lookups also seem to involve newer data) that causes locking problems under multiuse situations.

Also, you are not in control of the keys in an autonumber situation, your database is.  They are solely incremental, always generate larger numbers, and you can never reuse lower numbers already allocated, even when their identified rows are long deleted.

Your answer is correct about the autonumber field, but your advice on their use is absolutely horrid.  

bknouseAuthor Commented:
Why in Access 95 (and 97) do they have the AutoNumber field that can be set to Random or Increment, yet that property is not available through VB?  I am trying to copy a new structure created for a table through code to many disk copies.  The primary key is an autoincrement field with a property of random.  When I create the field as simply dbAutoIncrField attribute, I only get the increment sequential property.  Why can Access do it and you can't in VB?

Regarding the side issue of hot spots and sequential increasing keys, see the following from SQL server help:

While row-level locking is not a substitute for a well-designed application, there are specific scenarios where it is especially useful. Row-level locking is useful when a hotspot develops on tables structured as a sequential file. With SQL Server, hotspots can occur when records are inserted at the end of a table and one of the following conditions exists:

·      A table does not have an index.
·      A table has a nonclustered index.
·      A table has a clustered index with a monotonically increasing key (for example, a clustered index on an identity column).

When concurrent users try to insert data into the table's last page and contend for exclusive page access, a hotspot results. To alleviate these performance bottlenecks, enhancements to the lock manager in SQL Server 6.5 provide row-level concurrency for INSERT operations. Properly implemented IRL increases the speed of multiuser INSERT operations. The IRL operations occur in all data pages and in all levels of an index.

VB COUNTER type is only autoincrement on data type definition.  If you want random counter, why not define a source table using MS Access, then use the .CopyObject method to get  your template source table duplicated.

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
bknouseAuthor Commented:
Yes, that's the answer!   Thanks.
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Visual Basic Classic

From novice to tech pro — start learning today.