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Received:April 22, 2009
Received:April 22, 2009
中文摘要: SQL 语句在表达具有全部值语义时需要使用谓词NOT EXISTS 构建复杂的多层嵌套结构，学习者学习起来难度大，易出错。元组关系演算可以充分表达全部值语义，通过应用实例探讨了元组关系演算表达式转换为SQL 语句的转换规则，对学习SQL 语句者非常有帮助。
中文关键词: SQL 元组关系演算 全称量词 存在量词 转换规则
Abstract:SQL phrases require the use of predicate NOT EXISTS to construct complicated nested query in order to
express the full value meaning. Practitioners find it very difficult to write and easy to make errors. Tuple relational calculus can fully express such meaning. This paper uses examples to discuss and demonstrate trans formation rules when trans forming a tuple rel ational calculus expression to a SQL query, which is very helpful to SQL query learners.
keywords: SQL tuple relational calculus universal quantifier existential quanti fier trans form ation rules
文章编号： 中图分类号： 文献标志码：
基金项目:
| Author Name | Affiliation |
| XING Quan | 浙江工业大学 之江学院 经贸管理分院 浙江 杭州 310024 |
| Author Name | Affiliation |
| XING Quan | 浙江工业大学 之江学院 经贸管理分院 浙江 杭州 310024 |
引用文本：
邢泉.含有全部值语义的SQL 查询.计算机系统应用,2010,19(1):169-170
XING Quan.SQL Queries with Full Values.COMPUTER SYSTEMS APPLICATIONS,2010,19(1):169-170
邢泉.含有全部值语义的SQL 查询.计算机系统应用,2010,19(1):169-170
XING Quan.SQL Queries with Full Values.COMPUTER SYSTEMS APPLICATIONS,2010,19(1):169-170
