Domain-Oriented Relational Languages
Domain-Oriented Relational Languages
复制标题
面向领域的关系语言
DOI：
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发表时间：
1977
期刊：
影响因子：
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通讯作者：
A. Pirotte
中科院分区：
文献类型：
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作者：
M. Lacroix;A. Pirotte
关系数据库语义的观点在于认为数据库域表示主题的对象集，并且关系表示这些对象之间的各种关联。该视图由查询语言支持，其中关系数据库的域上的每个变量范围和谓词对应于由关系建模的关联。
本文定义了两种面向领域的关系语言。 DRC 是一种多分类演算，通过定义变量类型和类型检查规则来强调域的结构作用。 ILL 是一种类似英语的语言，它完全建立在嵌套其他表达式的表达式结构之上。
“领域语言”与“元组语言”形成对比，“元组语言”将关系 n 元组作为基本对象进行操作。直接操作域和域值可以更直接地与关系表达的语义交互，并产生更简单、更类似于英语的语言。
A view of the semantics of a relational data base consists in considering that the data base domains represent the sets of objects of the subject matter and that the relations represent various kinds of associations among these objects. This view is supported by query languages where each variable ranges on a domain of the relational data base and predicates correspond to the associations modeled by relations.
This paper defines two domain-oriented relational languages. DRC is a many-sorted calculus, where the structural role of domains is emphasized by defining types for variables and type-checking rules. ILL is an English-like language, which is wholly built upon a structure of expressions nested inside other expressions.
"Domain-languages" are contrasted with "tuple languages", which manipulate as basic objects the relation n-tuples. Directly manipulating domains and domain values interacts more directly with the semantics expressed by the relations and produces simpler and more English-like languages.