A conceptual data diagram provides a graphical view of the conceptual structure of an information system, and helps you identify the principal entities to be represented, their attributes, and the relationships between them.
In the following example, the Teacher and Student entities inherit attributes from the
Person parent entity. The two child entities are linked with a one-to-many relationship
(a teacher has several students but each student has only one main teacher) and the
other entities are linked through one-to-many or many-to-many relationships:
Tool |
Description |
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Data Item - An elementary piece of information. See Data Items (CDM). |
Entity - A person, place, thing, or concept that is of interest to the enterprise. See Entities (CDM/LDM). |
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Entity Attribute - An elementary piece of information attached to an entity. See Attributes (CDM/LDM). |
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Domain - A set of values for which a data item is valid. See Domains (CDM/LDM/PDM). |
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Identifier - One or many entity attributes, whose values uniquely identify each occurrence of the entity. See Identifiers (CDM/LDM). |
One-Many, One-Many Dependent, Many-Many Relationship - A connection between entities (ER modeling methodology). See Relationships (CDM/LDM). |
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Inheritance - A relationship that defines an entity as a special case of a more general entity. See Inheritances (CDM/LDM). |
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Association - A connection or association between entities (Merise modeling methodology). See Associations and Association Links (CDM). |
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Association Link - A link that connects an association to an entity. See Associations and Association Links (CDM). |