一种交互式关系代数学习工具设计

摘要

The relational algebra ,query optimization and equivalent SQL language converted are the more important parts in the teaching of the database system .Students think that the relational database relational algebra doesn ’t play an important role in the DBMS ,because of the working principle of the query expression ,the optimization and conversion between the SQL language and relational algebra are too hard to intuitively be understood and mastered by students . Based on that LALR(1) grammar achieves a good interface ,it is an easy-to-relational algebra learning tool ,the learning tool allows the establishment of relational algebra expressions by using the graphical interface and can connect to DBMS (such as SQL SERVER) ,real time feedback of the query data ,so that students better understand the use of relational algebra and understand its importance .%关系代数查询、查询优化及转换为等价SQL语言是高校计算机相关专业的核心课程，也是数据库系统课程教学中的重要内容。查询表达、优化、与SQL语言之间转换的工作原理很难被学生直观地理解和掌握，因此学生认为关系代数在关系型数据库的实际执行中没有发挥重要作用。该文基于LALR（1）文法实现了一个界面良好、操作简单的关系代数学习工具。该关系代数学习工具允许通过使用图形界面连接关系型数据库管理系统（例如SQL SERVER），建立关系代数表达式，对关系代数表达式进行对错判断，实现查询数据的实时反馈，让学生更好地理解和学习关系代数。此工具已应用于该校计算机相关专业数据库系统的课程教学，取得了良好的效果。