The reference between tables with different key

Hi, I hope you can help me:

I has two different Apps, the first controls the flow of trucks we received daily, with this keeps to my client informed about the status that of their Operations and when arrive at my Warehouse. This Apps the table contains the Key: “Operacion:” these number is generated in automatic with the formule UNIQUEID()

we have many trucks by the day. so each truck contains a different key

the other app control what the contains every truck, and when pick up each carrier you material, this app change status of each pallet of “waiting for pick up” to “in route”
to create a link between these two tables, I did that every pallet the material contains the same code of truck:

my idea was link both tables in the app that my client see, in such a way that every time that the client search a truck can see the information about the material and if was pick up or is it still in my warehouse (This it is controled in the second app)

I have done this in other apps but I think that the two tables must share the same key. in this case
in this case is not possible because for the table that controls the material, if you used the key “Operacion:” only display one row and there are many.

very thank you for your comments