可视化空间数据库查询语言CQL

本文着重从语法、语义及语用三方面介绍了我们所开发的一个可视化空间数据库查询语言ＣＱＬ。该语言允许用户借助于可视化基本元素－－－卡片进行编程,实现对窨数据库的检索。用户查询语句是这些卡片的空间组合。该语言对查询结果的表示提供了多种形式：图形表示形式、正文表示形式、临时文件或三者的组合形式。     

STQing：一种时态GIS可视化查询语言

在GIS领域,时态属性日趋重要,很多数据库管理系统已经加入了时间和空间属性而成为空间数据库系统。本文在此基础上提出了时态可视化,并设计了一个可以适应时空变化能力的图标式可视化查询语言STQing。     

用Delphi开发通用数据库可视化查询器

用户建立数据库的目的之一就是为了能够方便有效地查询数据库中的数据,因此构造方便、高效的查询系统已成为设计数据库应用系统的主要目标之一。当今世界上绝大多数关系数据库采用的查询语言是工业标准的ＳＱＬ语言。笔者在数据库应用程序开发中,用Ｄｅｌｐｈｉ 开发了一个通用的数据库可视化查询器。用户可以根据自己的查询需要,在这个可视化查询器提供的操作面板上方便地、全方位地组织自己的查询语句。即用户可以决定：显示那些字段、记录,以哪种方式显示等等。该通用可视化查询器的查询界面如图１所示。１通用可视化查询的总体设计…     

VSQL图卡定义及编辑器实现

以图卡作为程序设计语言的基本语素，定义了一种可视化语言，用以解决空间数据库可视化查询问题，称为VSQL语言。文中主要介绍VSQL语言的语素－图卡的定义，并对图卡编辑器的C＋＋实现进行简介。     

地理信息查询语言发展趋势

作者首先分析了空间数据库查询语言的特征,然后总结出当前的主流地理信息查询语言是SQL查询语言及其扩展,最后指出可视化查询语言将是未来地理信息查询语言发展的一大趋势。     

面向对象数据库中SQL语义模型的研究

结构化查询语言SQL是关系数据库(RDB)中广泛使用的查询语言,主要有四大功能：查询,操纵,定义,控制,这构成了关系数据库的功能主体。面向对象数据库是由面向对象数据模型定义的对象集合,该集合中的对象反映了面向对象程序设计所支持的对象语义。核心的面向对象数据库系统可以用下列等式表达它的组成；     

一种异构数据库数据的直接转换技术

本文阐述了如何利用PowerBuilder与数据库系统连接和可视化编程的强大功能，实现了异种数据库的直接转换方法。该方法为用户提供了可视化集成界面，完成了分布在网络不同结点上的目前常用几种数据库（ORACLE、SYBASE、INFORMIX、MSSQLSrver、SQLanywhere和FoxPro）的两两互相转换。     

用SQL语言进行动态查询

数据查询是数据库管理系统(DBMS)核心操作，数据库系统的主要功能是通过数据库支持的数据语言来实现．SQL语言提供了SELECT语句进行数据库的查询，该语句具有灵活的使用方式和丰富的功能。在程序中根据需求临时组装SQL语句，可以实现语句可变、条件可变的动态查询的设计要求。     

一种适合多数据库系统的查询表示方法

1 引言随着分布计算和网络技术的不断发展,传统的数据库技术已越来越不能满足数据共享和互操作的需要。同时,已有的数据库系统又不可能全部丢弃.因而研制能同时访问和处理来自多个数据库中数据的多数据库系统已成为必然趋势。多数据库系统是解决已存的、异构的、分布的多个局部数据库系统之间数据共享和集成的问题。由于多数据库系统具有异构性、分布性和局部自治性的特点,使得多数据库查询处理与传统数据库查询处理有很大的不同。多数据库系统呈现给用户的是全局模式,用户使用全局查询语言提交对多数据库的查询,而所需的数据又必须从各局部数据库获得,所以必须将全局查询转换成与局部数据库对应的局部查询。在全局查询转换为局部查询的过程中,需要     

SQL语言中连接查询和嵌套查询

SQL（Structured Query Language)是目前数据库领域中非常实用、流行的主流语言。SQL语言集数据查询、数据操纵、数据定义和数据控制等功能于一体。而数据库的查询又是数据库的核心操作，也是我们最常用的操作。数据库的查询操作是通过SELECT语句来实现的，通过SELECT语句我们能从数据库中查询出我们所需要的各种数据。     

Enriching the conceptual basis for query formulation through relationship semantics in databases

The rapid increase in end-user computing calls into question the suitability of existing database query languages (DBQLs). Because the typical DB end-user is not a DB specialist, it is essential that DBQLs use concepts that are as close as possible to those in the end-users’ cognitive mental model and adopt interface techniques that are suited to end-users’ abilities. Concept-based query languages are well suited for this. This realization has motivated further research in conceptual, or semantic, query approaches. However, the primary focus in this field has been on semantic query optimization, not on query formulation. In this study, we address ourselves to the problem of formulation of queries using concepts. We propose a concept-based query language, called the conceptual query language (CQL), which allows for the conceptual abstraction of database queries and exploits the rich semantics of data models to ease and facilitate query formulation.The CQL approach uses the relationship semantics of semantic data models to render transparent the technical complexities of existing DB query languages. Association semantics are also used to automatically construct query graphs and pseudo-natural language explanations of queries, and to generate SQL codes. A set theoretic formalism for conceptual queries is developed and used. This paper discusses the design of CQL, its expressive power, its implementation, and the strategies for CQL query processing. The implementation of a CQL prototype is briefly discussed in this paper. User experiments were carried out extensively and showed the advantage of CQL over alternative languages such as SQL.     

面向路网连通关系的车辆轨迹数据查询技术研究

定位及通信技术的发展使获取和传输移动车辆的轨迹信息成为可能。从车辆轨迹数据中可以提取出大量的交通信息,这些信息是对交通状况的一个直接和全面的反映。但由于轨迹数据固有的网络特性及时空特性,使针对此类数据的查询成为一个难点,其中关键技术包括建立用于车辆轨迹数据的索引结构及其对应的轨迹数据查询语言。在比较现有轨迹数据索引结构的基础上,对轨迹数据查询语言的分类及其与索引结构之间的调用关系进行了初步的探讨,提出了面向连通关系的查询语言（connectivity-oriented query language, CQL）的定义、分类及实现方法,并简要讨论了车辆轨迹数据查询原型系统的结构和实现方法。     

The CQL continuous query language: semantic foundations and query execution

CQL, a continuous query language, is supported by the STREAM prototype data stream management system (DSMS) at Stanford. CQL is an expressive SQL-based declarative language for registering continuous queries against streams and stored relations. We begin by presenting an abstract semantics that relies only on “black-box” mappings among streams and relations. From these mappings we define a precise and general interpretation for continuous queries. CQL is an instantiation of our abstract semantics using SQL to map from relations to relations, window specifications derived from SQL-99 to map from streams to relations, and three new operators to map from relations to streams. Most of the CQL language is operational in the STREAM system. We present the structure of CQL's query execution plans as well as details of the most important components: operators, interoperator queues, synopses, and sharing of components among multiple operators and queries. Examples throughout the paper are drawn from the Linear Road benchmark recently proposed for DSMSs. We also curate a public repository of data stream applications that includes a wide variety of queries expressed in CQL. The relative ease of capturing these applications in CQL is one indicator that the language contains an appropriate set of constructs for data stream processing. Edited by M. Franklin     

基于Aurora系统的持续型查询语言设计与实现

随着新型数据应用的不断出现,针对流形态数据的数据流管理系统已经成为数据管理领域研究的新热点。针对目前通用数据流管理系统只支持基于操作符流图的查询表达方式这一不足,设计了一种新的持续型数据流查询语言,并在通用数据流处理系统Aurora上进行了实现。为验证新语言的表达能力,该系统使用新语言定义了数据流基准测试Linear Road Benchmark的查询集,在Aurora系统上部署运行。测试结果表明针对Linear Road Benchmark的测试用例,新语言具有较完备的语义和良好的表达能力。     

面向对象数据库的C宿主语言接口实现技术

面向对象的数据库管理系统（ＯＯＤＢＭＳ）通常都具备自身的查询语言，它以交互的方式供用户进行数据定义与数据操纵．除此之外，它还必须为程序员提供可在Ｃ、ＦＯＲＴＲＡＮ、ＰＡＳＣＡＬ等高级语言里嵌入使用查询语言的宿主语言接口．本文首先介绍这样一种Ｃ宿主语言接口Ｃ—ＯＳＤＬ，而后重点讨论它的实现技术，尤其是将Ｃ—ＯＳＤＬ命令转换成ＳＱＬ语句的翻译算法以及使用ＳＱＬ实现支持导航式查找的指针层次管理方法．文中讨论的Ｃ—ＯＳＤＬ实现技术以及最初的接口设计是面向对象的数据库技术的深入探讨．     

RELOOP, an algebra based query language for an object-oriented database system

In most object-oriented databases, as opposed to value-oriented databases, data are accessed by a programming language instead of a declarative query language. End users do not have a simple tool to perform their queries. This paper is concerned with the definition of an SQL-like query language on top of the O₂ object-oriented database system. We study the influence of the object-oriented paradigm on a query language, describe our language through examples, define its semantics by means of an algebra and sketch the compilation of RELOOP in one of the languages supported by the O₂ system.     

CHIQL的多语句查询特征及其优化处理

CHIQL（Chinesequerylanguage）是一个正在开发中的中文数据库查询语言．为满足各种用户的需要，CHIQL在设计上具有如下的特点：符合中国用户思维方式的较自然的中文表述方式；过程化与非过程化相结合的多语句查询．对CHIQL而言，在实现上与传统SQL的最大区别在于它的多语句查询处理技术方面．本文在描述了CHIQL语言特征之后，重点讨论了多语句查询独特的优化问题，提出了基于语句合并的优化方法，并定性地分析了效率改善情况．     

Generalized Query-By-Rule: a heterogeneous database query language

This paper describes the design and implementation of a high-level query language called Generalized Query-By-Rule (GQBR) which supports retrieval, insertion, deletion and update operations. This language, based on the formalism of database logic, enables the users to access each database in a distributed heterogeneous environment, without having to learn all the different data manipulation languages. The compiler has been implemented on a DEC 1090 system in Pascal.     

Query language feature analysis by usability

Over the last decade many database management systems have been developed with one or more query languages for user manipulation and modification of data. This paper presents the results of a comparative analysis performed on eighteen query languages. The purpose of this analysis is to identify and categorize the features which influence the usability of the language. To this end, seven broad categories are detailed: data models, language functions, expression complexity, language format, environment, intended user expertise and interface facilities. These categories are described with examples from the languages. The framework this categorization begins to develop may be useful to perspective users as well as new language designers.