1NF要求每个单元格内只能存储单一值，禁止多值复合。请参考下表。通过确保每单元格内值的单一性，达到1NF标准。2NF强调非主键属性对主键的完全依赖，禁止部分依赖现象。以PeopleType与ID作为复合主键为例。为使表格符合2NF，需将部分依赖属性（如Building）分解至单独表格。3NF关注消除传递依赖，确保非主属...
3NF:表内不能存在传递依赖关系,非主属性只能和主键有依赖关系。不能像下面: 主键是ID和Name复合主键,Program和ID与Name有依赖关系,但ProgramLeader和非主键的Program有依赖关系,ProgramLeader需要通过Program才能传递依赖到主键。所以不是3NF。 把ProgramLeader分解到另外的表内,下面的表符合3NF: *** BCNF:不能存在非...
First Normal Form also known as 1NF Second Normal Form or 2NF Third Normal Form or 3NF Boyce-Codd Normal Form or BCNF Fourth Normal Form or 4NF Fifth Normal Form or 5NF or PJNF (Project-Join Normal Form) Q. What is a Primary Key in DBMS?
2NFA relation will be in 2NF if it is in 1NF and all non-key attributes are fully functional dependent on the primary key. 3NFA relation will be in 3NF if it is in 2NF and no transition dependency exists. BCNFA stronger definition of 3NF is known as Boyce Codd's normal form. ...
–1NF (First Regular Kind). –2NF (Second Typical Form). –3NF (Third Typical Kind). –BCNF (Boyce-Codd Regular Type). –4NF (4th Regular Kind). –5NF (5th Normal Form). –6NF (Sixth Regular Kind). The Theory of Database Normalization inSQLis still being established even more. Fo...
This Tutorial will Explain what is Database Normalization and various Normal Forms like 1NF 2NF 3NF And BCNF With SQL Code Examples.