Chapter 3.txt

A statement that defines or constrains some aspect of the business. It is intended to asset business structure or to control or influence.

(E-R diagram) A detailed, logical, and graphical representation of the entities, associations, and data elements for an organization or business area.

The number of instances of entity B that can (or must) be associated with each instance of entity A.

• An entity type that associates the
• instances of one or more entity types and contains
• attributes that are peculiar to the relationship
• between those entity instances. (3)

• A property or characteristic of an entity or relationship
• type that is of interest to the organization. (3)

• A relationship between the instances
• of two entity types. (3

• An attribute that has meaningful component
• parts (attributes). (3)

• An identifier that consists of a composite
• attribute. (3)

• The number of entity types that participate in a
• relationship. (3)

• An attribute whose values can be
• calculated from related attribute values. (3)

• A collection of entities that share common
• properties or characteristics. (3)

• A graphical representation of an entity-relationship
• model. (3)

• A logical representation
• of the data for an organization or for a business area
• using entities for categories of data

An association between two or more terms. (3)

• An attribute (or combination of attributes)
• whose value distinguishes instances of an entity
• type. (3)

• The entity type on which the
• weak entity type depends. (3)

• The relationship between a weak
• entity type and its owner. (3)

• An attribute that may take on more
• than one value for a given entity (or relationship)
• instance. (3)

• for every entity (or relationship) instance with which
• it is associated. (3)

• An association between (or among)
• entity instances where each relationship instance
• associates exactly one entity instance from each participating
• entity type. (3)

• A meaningful association between (or
• among) entity types. (3)

• An attribute that must have a value for
• every entity (or relationship) instance with which it is
• associated. (3)

• An attribute that cannot be
• broken down into smaller components that are meaningful
• to the organization. (3)

• An entity that exists independently of
• other entity types. (3)

• A word or phrase that has a specific meaning for the
• business. (3)

• A simultaneous relationship among
• the instances of three entity types. (3)

• A time value that is associated with a data
• value, often indicating when some event occurred
• that affected the data value. (3)