IDEF1X (Integrated Definition 1, Extended  IDEF1X narrows the definition of entities, attributes, and relationships  IDEF1X adds the notion of domains which is not present in the E-R model  IDEF1X introduces new symbology and hierarchy of views

IDEF1X vs. Extended E-R Extended E-RIDEF1XRemarks Entity Same Attribute Same Relationship Same 1:1 and 1:N Relationship Non-Identifying Connection Rel’ship HAS-A M:N RelationshipNon-Specific Rel’ship ID-Dependent Rel’shipIdentifying Rel’ship Weak Entity, ~ID-DepNone Supertype EntityGeneric EntityIS-A Subtype EntityCategory EntityCategories are mutually exclusive NoneDomain

IDEF1X RELATIONSHIPS  Non-Identifying Connection Relationship Equivalent to HAS-A relationships in E-R (1:1 or 1:N) DeptNameSerialNumber BudgetCode OfficeNumber Type Size Material DEPARTMENTFURNITURE DEPARTMENTFURNITURE 1:N A DEPARTMENT is not required to have any FURNITURE, but every piece of FURNITURE must belong to one, and only one, DEPARTMENT. Default relationship is 1:N as shown above

IDEF1X RELATIONSHIPS  Non-Identifying Connection Relationship DeptNameSSN BudgetCode OfficeNumber Name Phone JobCode DEPARTMENTEMPLOYEE DEPARTMENTEMPLOYEE 1:N A DEPARTMENT must have at least one, and can have many, EMPLOYEEs, but an EMPLOYEE need not belong to a DEPARTMENT. If Child entity is required, then add P; if Parent optional, add diamond p

IDEF1X RELATIONSHIPS  Non-Identifying Connection Relationship BadgeNumberSSN IssueDate IssuedBy Name Phone JobCode BADGEEMPLOYEE BADGEEMPLOYEE 1:1 An EMPLOYEE must have one, and only one, BADGE and a BADGE belongs to one, and only one, EMPLOYEE. 1:1 Relationship 1

IDEF1X RELATIONSHIPS  Non-Identifying Connection Relationship SerialNumberSSN Make Model DiskCapacity Name Phone JobCode COMPUTEREMPLOYEE COMPUTEREMPLOYEE 1:1 An EMPLOYEE may have zero or one COMPUTER, and a COMPUTER need not belong to any EMPLOYEE. 0:1 Relationship Z

IDEF1X RELATIONSHIPS  Identifying Connection Relationship Same as an ID-Dependent relationship in Extended E-R BuildingNumber ReceptionPhone NumFloors ParkingLot BUILDING OFFICE BUILDING 1:N A BUILDING may be connected to 0, 1, or many OFFICES; an OFFICE must be associated with a BUILDING. 1:N Relationship OFFICE OfficeNumber BuildingNumber NetPortNumber PhoneNumber MaxCapacity Note: Parent cannot be optional (“P”)

IDEF1X RELATIONSHIPS  Non-Specific Relationships Many-to-many (M:N) relationship CourseId CourseName Credits COURSESTUDENT COURSE M:N A COURSE may have many STUDENTs and a STUDENT may enroll in many COURSEs. M:N Relationship STUDENT Note: IDEF1X cannot represent min cardinalities for M:N StudentId StudentName Curriculum

IDEF1X RELATIONSHIPS  Categorization Relationships Generalization/subtype relationship in Extended E-R SSN Name Phone JobCode EMPLOYEE LevelCode LastBonus HourlyRate VacationDays Title Language OS YearsExperience Language TECH_WRITERPQA_ENGINEERPROGRAMMERSTAFFMANAGER Z Z ZZ Z ZZ JobCode