| 基于5VL的含空值关系数据库的选择运算 |
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| 引用本文： | 严丽,马宗民.基于5VL的含空值关系数据库的选择运算[J].微电子学与计算机,1998,15(4):52-54. |
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| 作者姓名： | 严丽 马宗民 |
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| 作者单位： | 辽宁工运学院!沈阳，110168，中科院沈阳自动化研究所!沈阳，110015 |
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| 摘 要： | 本文首先介绍了文献［1］给出的基于空值完全语义的五值逻辑（5VL），定义了基于5VL的比较运算和逻辑运算的运算规则，并以此为基础结出了一般条件表达式下选择运算的处理策略和实现算法。
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| 关 键 词： | 空值 关系数据库 五值逻辑 选择运算 |
Selecting Operation in Relational Database Containing Null Value Based on 5 Valucd Logic |
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| Yan Li.Selecting Operation in Relational Database Containing Null Value Based on 5 Valucd Logic[J].Microelectronics & Computer,1998,15(4):52-54. |
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| Authors: | Yan Li |
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| Abstract: | In this paper, 5 valued logic (5VL) based on full semantics of null value in 1] is presented firstly, and then comparative calculation and logical calculation based on 5VL are defined. The processing policy and realizing algorithm of selecting operation under common conditional expression are given at the end of this paper. |
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| Keywords: | Null value Relational database 5 Valued logic Selecting operation |
| 本文献已被 CNKI 维普 等数据库收录！ |
