Chapter 3 Building Conceptual Data Models

Conceptual Diagram Basics

A conceptual diagram allows you to define the logical structure of a database.

You can create the following objects in a conceptual diagram:

Object	Tool	Symbol	Description
Domain	[none]	[none]	Set of values for which a data item is valid. See Domains (CDM).
Data Item	[none]	[none]	Elementary piece of information. See Data Items (CDM).
Entity			Person, place, thing, or concept that has characteristics of interest to the enterprise and about which you want to store information. See Entities (CDM).
Entity Attribute	[none]	[none]	Elementary piece of information attached to an entity. See Attributes (CDM).
Identifier	[none]	[none]	Entity attribute, or a combination of entity attributes, whose values uniquely identify each occurrence of the entity. See Identifiers (CDM).
Relationship			Named connection or relation between entities (Entity Relationship (ER) modeling methodology). See Relationships (CDM).
Inheritance			Special relationship that defines an entity as a special case of a more general entity. See Inheritances (CDM).
Association			Named connection or association between entities (Merise modeling methodology). See Associations and Association Links (CDM).
Association Link			Link that connects an association to an entity and on which you define the cardinality an entity has relative to another. See Associations and Association Links (CDM).