实体完整性

通过数据结构映射（表结构映射和表联系映射）和数据完整性映射（实体完整性映射和参照完整性映射）的研究，详细地讨论了XML与关系模型之间的映射规则。

With the research of data structure mapping ( table structure mapping and table relation mapping ) and data integrity constraint mapping ( entity integrity mapping and reference integrity mapping ), the mapping rules between XML documents and relational model are detailed discussed .

本文阐述在VISUALFOXPRO中，如何保证数据库系统的数据完整性，即怎样设置实体完整性、域完整性、参照完整性。

This article elaborated how to guarantee the data integrality of the database system , that is how to establishing the entity integrity , the domain integrity , the reference integrity , in the Visual Foxpro environment .

求解关系模式的候选键是关系模型设计的基础，基于关键字的实体完整性和引用完整性是最基本的约束，也是最重要的约束。

Both entity integrity and referential integrity based on primary key are two important kinds of constraint .

在转换过程中保证了数据的实体完整性、域完整性以及引用完整性。

In the conversion process , it ensures the entity integrity of the data , domain integrity and referential integrity .

转换过程可保留关系数据库的实体完整性约束、参照完整性约束和绝大部分的用户自定义完整性约束。

The conversion process can retain the relational database 's entity integrity constraint referential integrity constraint and most of customing integrity constraint .

最后，通过实验表明，上述方法能够高效的完成异构关系数据库数据抽取，并且保证了被转换关系数据的实体完整性和参照完整性。

At last , through the experiments show , the method can efficiently finish heterogeneous relational database data extraction , and ensure the physical integrity , reference integrity of the extracted relational database .

针对该模型的不足，本文增加了一个新的描述实体完整性状态的特征域&完整性特征域，并提出了它的形式化定义。

Integrity , multiplicity , dependency , and inheritance , in which the characteristic dimension ' integrity ' is to describe the integrity status of objects , and then the integral definition of our model is presented .

该模型可以较好地保持特征实体的完整性，数据冗余较少，适合于在现有的GIS软件中组织时空数据。

This model has the advantage of keeping the integrality of feature entity and less data redundancies , and is easy to organize the spatio-temporal data in the traditional GIS .

在网格计算中，如何认证远端实体的完整性状态，对于网格安全具有十分重要意义。

In Grid computing , how to assure the remote entity integrity is of greaf sense for grid security .

充分利用三维实体数据的完整性，实现各层次二维图形的自动生成和结构力学分析所需的数据模型的自动建立；

Making full use of integrity of 3D model information , the system automatically generates various kinds of 2D drawings and constructs the data model for structural analysis .

此策略在可信文件（与上面的实体相同）的完整性检查失败时停止那些文件的加载。

This policy stops the loading of the trusted files ( same as the entities above ) if integrity checks fail for them .