12 chen p p . the entity - relationship model - toward a unified view of data 例如,定義一個問題歸約范疇有所有的問題類組成。
The entity - relationship model has gained acceptance in database design and is widely used in practice 實質(zhì)-聯(lián)系的模型已經(jīng)得到數(shù)據(jù)庫的接收設(shè)計并且廣泛地被用于練習(xí)。
The entity - relationship model and the object - oriented model are representatives of the class of the object - based logical models 實質(zhì)-聯(lián)系的模型和物件定向的模型是以物件為基礎(chǔ)的合乎邏輯的模型類別的代表。
The object - oriented model includes many of the concepts of the entity - relationship model , but represents executable code as well as data 物件定向的模型含實質(zhì)-聯(lián)系的模型許多觀念,但是表現(xiàn)可運行的碼和數(shù)據(jù)。
Some authors draw a clear line between the design models , typically uml models or entity - relationship models which are supposed to be abstract , and the xml schemas which include lots of implementation details 一些作者在設(shè)計模型和xml模式之間劃了一條清晰的界線,設(shè)計模型通常是uml模型或?qū)嶓w-關(guān)系模型,被認(rèn)為是抽象的,而xml模式則被認(rèn)為包含大量的實現(xiàn)細(xì)節(jié)。
Database of data warehouse and traditional operational database are compared in this paper , then the design of " normative " operation system is reviewed , four typical data models are introduced - entity - relationship model 、 object model 、 dimensional model and star model 摘要比較了數(shù)據(jù)倉庫數(shù)據(jù)庫與傳統(tǒng)操作型數(shù)據(jù)庫,回顧了“規(guī)范的”操作型系統(tǒng)設(shè)計,介紹了四種典型的數(shù)據(jù)模型實體關(guān)系模型、對象模型、維模型和星型模型。
In addition , it puts forward a nested temporal db , which , with stronger expressive ability than others , is a breakthrough to entity - relationship model and is referred to as nter model . it also verifies the expressive ability of nter when it is applied to sidss . finally , in view of the features of sidss and the current status of salary distribution system , it conducts initial study of the sidss based on temporal - spatial relationship and the sidss with a temporally - driven knowledge database , with the aim for us to develop a consummate sidss system in the future 本文中,介紹了時態(tài)數(shù)據(jù)庫的基本概念、發(fā)展、特點和分類;結(jié)合sidss的背景、特色及體系結(jié)構(gòu),詳細(xì)討論了sidss的時態(tài)性及其數(shù)學(xué)模型,指出將時態(tài)數(shù)據(jù)庫應(yīng)用到sidss并作進(jìn)一步的研究是必然趨勢,并在此基礎(chǔ)上研究了時態(tài)數(shù)據(jù)庫系統(tǒng)的模型;在探討了幾種模型之后,打破實體-關(guān)系類的模型的框框,提出了一個表達(dá)能力較強(qiáng)的嵌套時態(tài)數(shù)據(jù)模型,稱之為nter模型( nestedtemporalentity - relationshipmodel ) ,并驗證將其應(yīng)用到sidss系統(tǒng)中的表達(dá)能力;最后針對sidss的特點以及目前工資管理系統(tǒng)的狀況,進(jìn)一步對基于時空關(guān)系的sidss系統(tǒng)、由時態(tài)驅(qū)動知識庫的sidss系統(tǒng)進(jìn)行初步探討,以期今后對開發(fā)更完善的引) ss系統(tǒng)作進(jìn)一步的研究。
Topics include : relational databases , sql ( structured query language ) ; types , relations , relational algebra , integrity , view ; functional dependency theory , normalization , semantic modeling , entity - relationship modeling , conceptual database design ; concurrency control , security ; database and web connectivity , xml 主題包括:關(guān)聯(lián)式資料庫、 sql (結(jié)構(gòu)查詢語言) ;資料類型、關(guān)聯(lián)、關(guān)聯(lián)式代數(shù)、完整性、景觀表;功能依附理論、正規(guī)化、語義塑模、實體關(guān)聯(lián)塑模、概念性資料庫設(shè)計;同時操作控制、安全;資料庫與網(wǎng)頁連結(jié)、 xml (可擴(kuò)展標(biāo)示語言) 。