There is a one-to-one relationship between a Sales Order and a Drop Ship/Special Order Purchase Order

This is defined using the fields on the Sales Order:

• Purchase Order No.
• Purch. Order Line No.

or

• Special Order Purchase No.
• Special Order Purch. Line No.

In reality, this may not work. For example, stock for a supplier may be purchased from multiple vendors, or across multiple purchase orders. It is not practical to split a Sales Order into multiple lines (current work around).

Potential solutions would be table for one-to-many relationship between SO and PO:

• SO No.
• SO Line No.
• PO No.
• PO Line No.

Alternatively, the Purchase Order No. fields could be dropped from the sales line, instead lookup by filtering on the fields on the Purchase Line?