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When creating a table and a database in do the foreign keys need to be unique?
For example
Table: Manifest
Manifest_Barcode - PK
Vehicle_reg - FK
weight
description
Table: Vehicle
vechicle_reg - PK
employee_ID - FK
make
model
Table: Drivers
employee_ID - PK
vechicle_reg - FK
name
adress
phone_Number
year
Or, can I use the same foreign key in 2 different tables? Like the above?
It is completely appropriate and quite normal to have multiple FOREIGN KEYs that refer to the same PRIMARY KEY. They are not the same FOREIGN KEY (they will each build a separate index to use in enforcing the key), they are different FOREIGN KEYs with similar definitions.
Note that you will have to create the table
vehicle1before declaring either of the FOREIGN KEYs.