After insert trigger on a table that has a Primary Key

Hi Ahmad, 

I'm not sure to fully understand your need, but please consider the following bullet :

- From performance perspective, triggers are not the best way to go.

- Why don't you allow your Order record to be childless, and then add a record into the Delivery table after, via user interface typically ? 

Finally, to keep your solution in place : 

- Define your DeliveryID column as a BigInt, and enable the Identity property to True (ref your screenshot). Then the value of your DeliveryID column will be automatically incremented for each new record.

- Define your DeliveryID column as a UniqueIdentifier, and define a default value as new_sequentialid().

Hope this helps.

Fred.M.