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[dL1727]

I currently have a table called “Payment History.” Though there are numerous fields, my question only pertains to two particular ones LineID and PoID (representing Line ID and Purchase Order ID respectively). There is a one-to-many relationship between these two fields (i.e. a single purchase order can have numerous lines, however one line can only have one purchase order). What I want to do is create a form where the user first enters the PoID number (when form is blank) that automatically fills in the field LineID with the next number available (such that every LineID entry would therefore be unique). Here is an example of what I would like the form to do:

Table: Payment History
LineID PoID
656565.01 656565
656565.02 656565
737373.01 737373.01
So that in the form when the user enters 656565, the database automatically fills in LineID as 656565.03

 

[Galaxiom]

Keep the IDs in separate fieldsa. There really is no point combining the POID and LineIDs like that and you will just make unnecessary work at many other points in the project.

The records can have unique identity using a composite key based on the two fields.