Database Paradigm Design __ Database

Database relational paradigm has "1NF", 2nf,3nf,4nf,5nf,bcnf

1NF: In the Design database relationship R, each property can not be decomposed into units, then R is 1NF. For example: name, telephone this is 1NF

2NF: in Relationship R (x,y), all attributes are entirely determined by a candidate keyword. Unique identification for the record

3NF: is a redundant constraint on a field, and any field cannot be derived from another field. That is, there is no redundancy in the field.

BCNF: Refers to the R (X,y) relationship in which all attributes do not rely on any candidate keywords, bcnf contains 1nf,2nf,3nf content. Design should be as reduced as possible