Objectives:
Objectives Identify the need for an intersection entity
Create an intersection entity
Create a UID for the new entity
Identifying the Problem:
Identifying the Problem TITLE SUPPLIER supplied by supplier of In which entity would you store the attribute purchase price? From this diagram, can you tell which supplier instance provides “Casablanca”? # * prod code
* name # * supplier no
* name
Intersection Entities:
Intersection Entities CATALOG ITEM available as SUPPLIER supplier of TITLE TITLE # * prod code
* name # * supplier no
* name * purchase price
for for
Unique Identifiers:
Unique Identifiers available as CATALOG ITEM SUPPLIER supplier of TITLE TITLE # * prod code
* name # * supplier no
* name * purchase price
for for CATALOG ITEM available as SUPPLIER supplier of TITLE TITLE # * prod code
* name # * supplier no
* name # * item num
* purchase price
for for OR
Summary:
Summary Identify the need for an intersection entity
Create an intersection entity
Create a UID for the new entity