Boyce-Codd Normal Form is a generalization of Second and Third Normal Forms. There are a couple of requirements to be in Boyce-Codd Normal Form. First, your table must be in First Normal Form. This means that:
- Every entity (row) has a consistent shape. This is something relational databases do for you automatically: you can’t create a table where one entity has an attribute (column) but the next entity doesn’t.
- Every entity has a unique value. You can uniquely identify any particular row.
- Every attribute is atomic: you don’t try to pack more than one value into a single attribute.
- There are no repeating groups of attributes, like PaymentMethod1, PaymentMethod2, PaymentMethod3, etc.
The other half of BCNF is that every determinant on an entity is a key.
Also click through for an iterative, easy-to-follow process to get to BCNF.