I have a lineitems table related to an items table called material.
Contents of a layout:
The layout shows records from the lineitems table,
A portal shows record from material,
A field (materialIDfk) from lineitems table is the foreign id linked to the parent id on material (materialIDpk).
First record of my layout
I type the 5 materialIDpk's numbers in the materialIDfk's field.
Each ID is representing one item contained in the material table, using the enter key at the end of each material's id number, the portal shows the list of related items. Great if I got only one record in this layout.
Now here is my problem:
If I got two or more records in my layout and I type the same ID number in the second layout record, I'd love Filemaker to send a warning or do something to avoid that this specific number is used multiple times.
The goal is that the each unique item ID number must be used only in one record in the layout described above.
How can I do that?
Thank you so much in advance,