| 释义 |
functional dependence
函数相关
In data base, an indication of the interrelationships of attributes in a relation. Attribute A of a relation R is functionally dependent of attribute B of relation R if, at every instant of time, each value of B has no more than one value of A associated with it.
数据库中,某种关系内的各属性之间相互关系的一种表示。关系R的属性A函数相关于关 系R的属性B的条件是:在每个时刻,对B的每个值都只有一个A值与它相关。 |