Question

A relation is in first normal form if every non-primary key attribute is functionally dependent on the whole primary key.

Answer 1

A relation in 1NF means that every non-primary key attribute is functionally dependent on the whole primary key.

Step-by-step explanation:

A relation in the context of databases refers to a table with columns and rows. First normal form (1NF) is a property of a relation where every non-primary key attribute is functionally dependent on the whole primary key. This means that each attribute in the table must depend on the entire primary key and not just part of it.

For example, let's say we have a table called 'Students' with columns 'StudentID', 'FirstName', and 'LastName'. If 'FirstName' is functionally dependent on 'StudentID', meaning each 'StudentID' has a unique 'FirstName', then the relation is in 1NF.

However, if there is another column 'Grade' that depends on only a portion of the primary key such as 'StudentID', then the relation is not in 1NF since the non-primary key attribute 'Grade' is not fully dependent on the whole primary key.