2025年1月16日 · Converting an Entity-Relationship (ER) diagram to a Relational Model is a crucial step in database design. The ER model represents the conceptual structure of a …

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（ERM） （英語： Entity-relationship model）由美籍台湾人计算机科学家 陈品山 发明，是 概念数据模型 的高层描述所 …

An entity–relationship model (or ER model) describes interrelated things of interest in a specific domain of knowledge. A basic ER model is composed of entity types (which classify the things …

2023年12月21日 · An Entity Relationship Diagram is a great tool to help you define, understand, and communicate the requirements of a system. It can be modelled at a high level (conceptual …

ER diagrams are used to model and design relational databases, in terms of logic and business rules (in a logical data model) and in terms of the specific technology to be implemented (in a …

Entity Relationship Diagram, also known as ERD, ER Diagram or ER model, is a type of structural diagram for use in database design. An ERD contains different symbols and connectors that …

2025年3月25日 · Database Modeling Entities Relationship Sets Relationship Sets with Attributes Roles Degree(度) of a Relationship Set Mapping Cardinality Constraints（映射基数约束） …

Entity Set: Collection of entities of a particular entity type at any point in time; entity set is typically referred to using the same name as entity type. Entities of an entity type need to be …

ER MODEL OVERVIEW ER model describes data in terms of: •Entities and entity sets • Objects •Relationships and relationship sets • Connections between objects •Attributes • Properties …

2024年12月31日 · ER Model stands for Entity Relationship Model is a high-level conceptual data model diagram. ER model helps to systematically analyze data requirements to produce a well …