Monday, September 13, 2010

Entity Life History Diagrams

An Entity Life History diagram is used to show the sequencing, iteration or timing of an entity. An Entity Life History (ELH) diagram represents the life cycle of entities within the database.

ELH Diagrams of Online Mobile Store:
Customer Entity Diagram:

Shopping Cart:
  •  The iterative nature of movement is shown by asterix (*)
  • Any one "movement" must be only one of the optional kinds listed. This is shown by the "o" in the upper right corner.