理学 数据库系统 释 data model 数据模型 数据库领域中定义数据及其操作的抽象表示方式。数据模型是数据库系统的核心和基础。各种数据库管理系统（DBMS）软件都是基于某种数据模型的。
data model 数据模型
数据库 数据库理论 释文 data model 数据模型
- National Provincial Museum Director Professional Management Cadres Training Class
- national public relations
- National Public Security Commission
- National Public Security Organs Cross-regional Case Handling Cooperation Platform
- National Public Security Work Conference in the New Era
- National Publishing Committee
- National Radio and Television Administration
- national radio and television editor and reporter, announcer and host qualification examination
- National Radio Astronomy Observatory
- National Radio,Film and television Academic Paper Award
- National Radio, Film and Television Academic Works Award
- National Railway Administration of The People's Republic of China
- National Railway Museum
- National Rainbow Coalition
- National Rally of Independents
- national reading rate
- National Reconciliation Week
- National Recovery Administration，NRA
- national recreational sports
- national reputation
- National Research and Development Agency Public Works Research Institute
- National Research Center for Certified Reference Materials
- National Research Center for Sustainable Hydropower Development
- National Research Institute of Cultural Heritage
- National Research Institute of Science and Technology for Environment and Agriculture