CS636 E-R and UML Class Diagrams 

Pizza E-R using * for MANY: (also menu_toppings and menu_sizes, separately)

pizza er

Pizza UML Class Diagram: also MenuTopping and MenuSize, separately

 pizza UML

 Singletons: these are the infrastructure objects whose methods form the APIs

Pizza project API singletons

Music E-R Diagram: using crow's feet for MANY end of relationships

 music ER

Music UML Class Diagram: because the Invoice "owns" its LineItems (not shared with other Invoices) the diamond is filled-in. Similarly with Product and Tracks.

music uml