David LaneHugh E. Williams
[entity-relationship] Entity-relationship modeling is a database modeling method, used to produce a type of conceptual schema or semantic data model of a system, often a relational database, and its requirements in a top-down fashion. Sign up to watch this tag and see more personalized ...
什么是E-R图 维基百科的解释如下,这里称为ER模型: ER模型,全称为实体联系模型、实体关系模型或实体联系模式图(ERD)(英语:Entity-relationship model)由美籍华裔计算机科学家陈品山发明,是概念数据模型的高层描述所使用的数据模型或模式图。 基本介绍 举例子 数据库设计(一):ER模型概念介绍 数据库设计步骤数据库的设...
AnEntity–relationship model (ER model)describes the structure of a database with the help of a diagram, which is known asEntity Relationship Diagram (ER Diagram). An ER model is a design or blueprint of a database that can later be implemented as a database. The main components of E-...
The entity-relationship model (ER) can be visualized in a diagram (ERD) to show a database's design, table, attributes, and relationships. Explore this through entities and tables, keys, and the idea of cardinality. The ER Diagram
RelationshipModelRelationshipModel实体实体--联系模型联系模型1.2DatabaseSystemConceptsEntitySetsEntitySets实体集实体集 Adatabasecanbemodeledas:数据库可由下列内容模型化 acollectionofentities,实体集合 relationshipamongentities.实体间的关系 Anentityisa―thing‖or―object‖intherealworldthatisdistinguishablefromall...
How would you model these relations to tables? Should the MedicalHistory & FemaleMedicalHistory tables share the same primary key (eg. mid)? Edit: This was what I had in mind, but I'm not sure it fits: database-design entity-relationship Share Improve this question Follow edited Jul ...
ER Model in DBMS stands for an Entity-Relationship model The ER model is a high-level data model diagram ER diagrams are a visual tool which is helpful to represent the ER model ER diagrams in DBMS are blueprint of a database Entity relationship diagram DBMS displays the relationships of e...
The entity-relationship (ER) data model is a well known semantic data model in database design. The paper develops a deductive-ER data model, Deductive-ER, which applies the ER approach to the design of deductive databases. Based on such a model, a deductive-ER data language, called Deduct...
必应词典为您提供Entity-relationship-model的释义,un. 实体关系模型;实体联系模型; 网络释义: 实体-联系模型;实体关联模型;个体关系模式;