Re: Identifying an Identifying Relationship

Dan Guntermann wrote:
> My confusion might stem on my reluctance to depend on tools such as ERWIN
> for modeling and design purposes, so any clarification would be appreciated.
>
> Concatenation of primary keys? Concatenation of any type of candidate key
> for identifying relationships, whether user-defined or system generated, is
> a new one on me. Does this mean that in what is termed a "parent-child"
> relationship, or even in an association relation for that matter,
> system-generated keys are concatenated together in a single attribute for
> the child relation?

No no. It only means that the PK of the child consists of the PK of the parent plus some attributes of its own. E.g. the PK of an 'Order line' will consist of the PK of 'Order' (pres. 'order number') plus something like 'line nr.'.

-- 
  Jan Hidders