Getting unique numbers for one numberseries (table)?
I have 4 tables: District ----> Owner ----> Calvesnumbers <---- Fencenumbers
District-table is related to Owner-table (owner has district as a field). Owner-table i related to Calvesnumbers-table (Calvesnumber has Owner as a field) and Calvesnumbers-table is related to Fencenumbers-table (Calvesnumbers has Fencenumbers as a field).. Everything is OK so far..
But I would like the Calvesnumbers-table to have unique calvesnumbers, based on unique Fencenumbers. This means that Fencenumber 1 can have a unique calvesnumber 1, and furthermore Fencenumber 2 can also have calvesnumber 1. But never can the Fencenumber 1 have calvesnumber 1 twice in the same Fencenumber.
Should i make another table here, or something else?!