I am modelling a database for a term project and I have come across something I do not have a definite answer to.
I was supplied with the following Entity-Relationship diagram:
So, as you can see, such diagram depicts the following entity types:
District, which has the attributes
Number(set up as Primary Key),
Delegate, that holds the attributes
Id(defined as Primary Key),
District is the strong entity type supporting
Delegate, but the cardinality of this relationship is 1:1. Up to this point, I have seen 1:M relationship cardinalities regarding strong/weak entities, and I know how to map those to tables, but in this case, I am not so sure, mainly because I do not know how I could get around the possibility of repeating
Delegates if the
Delegate.Id and the
District.Number were to be a composite key.
- What shall I do at the implementation level?
- Do I create a table to store
Delegateinstances, with the
Districtas the only key?
- Is my understanding of composites key wrong?