semantic constraints meaning in English
语义约束
Examples
- The relax ng compact syntax provides a much less verbose , and easier to read , format for describing the same semantic constraints as relax ng xml syntax
Relax ng紧凑语法提供了一种格式用于描述与relax ng xml语法相同的语义约束，这种格式更简洁、更易于阅读。 - 2 ) based on xml keys which define the semantic constraints of xml document , we present a storing method , which stores xml documents while conserving their key constraints
2 )基于xml键约束的概念，提出了一种将xml文档保持xml键约束地映射到关系数据库中的方法。 - This bug occurs when stored data fails to satisfy certain syntactic or semantic constraints ; when software crashes due to an error , not in the coding , but in the data the code is manipulating
这种错误在已存储的数据不能满足某些句法或语义约束时发生；此时软件会因为代码操纵的数据中的错误而不是编码中的错误而崩溃。 - Aiming at this problem , the main research issues and achievements in this paper are as follows : bi - directional data transformation between rdb and xml with semantic constraints preserved for most of existing researches on static data transformation between xml and rdb , dtd is taken as the schema description language for xml , and the semantic constraints are often lost during the transformation process . to overcome these disadvantages , the author adopts xml - schema , a standard schema description language proposed by w3c to replace dtd , as the description method owing to its more powerful functions than dtd , and of course with the syntax much more complicated . after analyzing the constraints characteristics in both xml - schema and relational schema , a semantic constraints - preserved algorithm is proposed which can realize the bi - directional schema mapping between rdb and xml through a formalized description of xml based on regular tree and a general expression for relational schema based on direct graph approach
保留语义约束的xml与rdb双向静态数据转换技术现有研究大多采用dtd ( documenttypedefinition ，文档类型定义)作为xml的模式描述语言，并且在模式映射过程中丢失语义约束信息，本文分析了xml - schema ( xml - schema采用与dtd完全不同的语法，数据描述能力更强同时也更为复杂，已被w3c确定为替代dtd作为xml模式描述语言的标准)及关系模式的语义约束特征，通过基于正则树的xml形式化描述方法以及基于有向图的一般关系模式表示方法的研究，建立保留语义约束的xml - schema与关系模式的双向模式映射算法，实现了xml与rdb的双向数据转换，较好地解决了xml与rdb在静态数据转换层面的数据集成问题，可有效满足企业大量rdb数据面向xml的发布以及与日俱增的xml数据存入rdb的应用需求。