MVDF has to be the key?# Database - 数据库
c*e
1 楼
hi
If A->>B
exist in one relationship, say R(A,B,C),
and A will decide all the other attibutes, say, C will be decided by A, then
A should be a member of the key, right?
but somebody told me B has to be the key along with A because it's MVDF
of A. Somebody think the same way?
If A->>B
exist in one relationship, say R(A,B,C),
and A will decide all the other attibutes, say, C will be decided by A, then
A should be a member of the key, right?
but somebody told me B has to be the key along with A because it's MVDF
of A. Somebody think the same way?