Graphical objects used in the Entity Relationship Model
Entity type
Entity that represents an object for which you must record information. It can be one of the following:
- Normal; to represent a Logical entity (has a meaning to the real world and is comprised of one or more physical entity types) or a Physical entity (database tables in the LN applications)
- Associative; used to link other entity types
An entity in a diagram can have a Decomposed diagram linked to it. The graphical object is represented embossed.
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Linked Tables icon | Indicates that a database table is linked to the Entity Type |
Relationship (1:n)
Represents the relationship between the entity types. The cardinality of the relationship defines the expected number of related occurrences for each of the two entity types.
Subtype relationship
An indication that the supertype’s attribute also apply to (are inherited by) the subtype
Entity Relationship Diagram objects toolbar
| Button | Description |
|---|---|
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To insert an Entity that represents an object for which you must record information |
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To insert a relationship between two entity types |
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To insert a subtype relationship between two entity types |