Purpose of AutoIncrement field in dataverse?

[FerrDiBarnes]

What is the purpose of the auto incrementing field?    It allows duplicates,  and may create string-numbers out of order, meaning a number created last week was AAA-1010   and one created just now might be AAA-900 , AAA-1010 or AAA-2015.

The term auto increment is generally defined as:  Auto-increment allows a unique number to be generated automatically when a new record is inserted into a table

This is not the behavior here, so I am curious why dataverse autoincrement was created.

[a33ik]

Hello,

Here is the information about auto number columns - https://learn.microsoft.com/en-us/power-apps/maker/data-platform/autonumber-fields

If you want to guarantee the uniqueness of the value in the field you might combine your auto number field with alternate keys - https://learn.microsoft.com/en-us/power-apps/developer/data-platform/define-alternate-keys-entity

[FerrDiBarnes]

I see now that I read auto number to mean auto-incrementing, but MS calls it  auto number, "columns that automatically generate alphanumeric strings whenever they are created" .     But my question is why would you create an auto number field.    What use does it serve if it is not guaranteed to be unique or always incrementing?  

[Fubar · Accepted solution]

You use them as often you need a human readable identifier for a record (if you don't need human readable you can use the guid of the record which is also unique)

The sequence number that is generated is +1 every time a record is created for the Table that has the auto number and as such for a Table it is unique, except:

• Someone has re-seeded the auto number, then the next record will start from that reseed and this can lead to duplicates if the reseed value was less than the current sequence number
• Someone has left the field as editable and someone manually updates (or an automation updates) the field with a value that already exists (the sequence does not look at any updated values the sequence itself is managed out side the tables)

As indicated in the earlier post you can force uniqueness by implementing an Alternate Key on the field.