摘要
从关系代数中除法运算的定义出发,以实例分析和图表表示为工具,通过类比整数的除法运算阐明关系除法运算的本质含义,并给出关系代数中除法运算的基本运算表达式。解决以往除法运算的抽象定义难以被学生理解的不足,促进学生对知识点的透彻理解,取得较好的教学效果。
Gives the definition of division operation in relational algebra,illustrates its calculating steps through examples and graphic tools,discusses this operation＇s nature meaning by an analogy with integer division,and further expresses the division operation in terms of the basic algebra operators.This teaching reformation eliminates the students＇ difficulties of understanding abstract concepts,helps students to thoroughly master the division operation,and is proved with better education effects.
出处
《现代计算机》
2011年第10期42-44,共3页
Modern Computer
关键词
关系代数
除法运算
数据库系统
Relational Algebra
Division Operation
Database System
