(南京信息工程大学 信息与控制学院, 南京 210044)
摘 要:在已研究的模糊查询中,其逻辑连接均为and或or,具有一定的狭隘性,不符合自然语言表述的特点,也不能充分满足查询要求。引入模糊语言量词作为模糊逻辑连接词,同时引入权重,利用Zadeh 的模糊集合理论与SQL系统函数相结合,研究了基于模糊逻辑连接的带权重的模糊查询技术,进一步丰富了SQL模糊查询体系,提高了查询能力。
关键词:模糊集理论; 模糊语言量词; 模糊逻辑连接; 权重; 适配度
Fuzzy queries with weights based on fuzzy logic conjunctions
WANG Hui, ZHANG Yingchao
(Dept. of Information & Communication, Nanjing University of Information Science & Technology, Nanjing 210044, China)
The previous work studied such queries as simple queries, compound queries, multirelational queries, subqueries with weights and etc. Which solved fuzzy questions to some extent. But the logic connectives was always AND or OR, so the previous SQL queries had some limits. It didn’t adapt to the natural language and did not satisfies the queries. Based on Zadeh’s fuzzy theory, introduced fuzzy logic and weights to solve this kind of queries through the combinations of fuzzy theory and SQL functions, which would enrich fuzzy queries system, thus enabling more effective queries.
Key words:fuzzy theory; fuzzy linguistic quantifies; fuzzy logic conjunctions; weights; matching degree ......