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.

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
To insert an Entity that represents an object for which you must record information
To insert a relationship between two entity types
To insert a subtype relationship between two entity types