This brings to mind earlier arguments that instead of coming up with cures that do not seem to suit the illness ( only because there seems to be no takers ), perhaps the weak entities should be allowed to die a natural death.
12.
In entity relationship diagrams, ER diagrams a weak entity set is indicated by a bold ( or double-lined ) rectangle ( the entity ) connected by a bold ( or double-lined ) type arrow to a bold ( or double-lined ) diamond ( the relationship ).
13.
A classic example of a weak entity without a sub-type relationship would be the " header / detail'records in many real world situations such as claims, orders and invoices, where the header captures information common across all forms and the detail captures information specific to individual items.
