Basic Concepts of Entity-Relationship Model
Neso Academy・2 minutes read
The Entity Relationship Model (ER Model) defines data with entities, attributes, and relationships, with entities representing real-world things and attributes detailing properties. Attributes encompass various types like composite, simple, single-valued, multi-valued, derived, and stored, with null values indicating not applicable or unknown information.
Insights
- The Entity Relationship Model (ER Model) categorizes data into entities, attributes, and relationships, providing a structured way to understand and represent complex information systems.
- Attributes play a crucial role in defining entities by describing their properties, with various types like composite, simple, single-valued, multi-valued, derived, and stored, each serving a distinct purpose in data modeling and analysis.
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What is the Entity Relationship Model?
A conceptual model describing data entities, attributes, relationships.
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Summary
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Understanding the Entity Relationship Model in Data
- The Entity Relationship Model (ER Model) describes data as entities, attributes, and relationships.
- Entities are things in the real world with independent existence, such as objects with physical or conceptual existence.
- Attributes are properties that describe entities, like name, age, address, etc.
- Types of attributes include composite (dividable), simple (indivisible), single-valued (one value), multi-valued (set of values), derived (from other attributes), and stored (value source).
- Null values in attributes can signify not applicable or unknown information, with unknown further classified into missing or existence uncertainty.
