1.1NF(P328、P215)
In the relationalmodel, we formalize this idea that attributes do not have any
substructure. A domain is atomic if elements of the domain are considered to be
indivisible units. We say that a relation schema R is in first normal form (1NF) if
the domains of all attributes of R are atomic.
非第一范式的例子:
2.Boyce-Codd Normal Form
一般的分解为BCNF的方法:
创建第三范式的原因:(BCNF的缺陷)
3.3NF(Third Normal Form)
4.函数依赖集的闭包
逻辑蕴含的定义:
闭包的定义:
Armstrong公理及其进一步推出的规则:
进行求解的伪代码: