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，确保非主属性直接依赖主键，而非通过其他非主属性间接依赖。以下表示例中，Pro...
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...
Q. What are the different Normal Forms in DBMS? Following are the different Database Normal Forms: 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 ...
This table is now in BCNF as in both the functional dependencies left side part is a key.That's all about what is Normalization in database and what is 1NF, 2NF, 3NF and BCNF. In this tutorial, you have seen Normalization in SQL and figured out the different Normal forms of ...
–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...
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. ...
This Tutorial will Explain what is Database Normalization and various Normal Forms like 1NF 2NF 3NF And BCNF With SQL Code Examples.
数据库的三大范式包含:第一范式(1NF)、第二范式(2NF)、第三范式(3NF)。 第一范式(1NF):数据库表中的每一列都不可再分,也就是要满足原子性。所谓的原子就是最小的,不能再进行划分的。例如,如果有一个列是“部门岗位”,这实际上是可以进行划分的,应改为“部门”和“岗位”两列,这样才满足第一范式。
2) Second Normal Form (2NF)There are several conditions for keeping the second normal shape of the database table. These are the following -In the 2NF row, the table must be 1NF. In the second normal type, all non-key attributes depending on the primary key are completely functional....
i) First Normal Form (1NF) ii) Second Normal Form (2NF) iii) Third Normal Form (3NF) iv) Boyce-Codd Normal Form (BCNF) v) Fourth Normal Form (4NF) vi) Fifth Normal Form (5NF) vii) Domain/Key Normal Form (DKNF) In my previous blog,Database Normalization :: Part 1I’ve discus...