ERD ---> Relational Mapping

[Tommy]

I'm new to database design and management. I'm presently taking a
course in this area. At the moment I just wanted to know when you have
the following relationship:

Entity 1 <---Relationship----> Entity 2 Integrity Contraint is 1 to N
from Entity 1 to Entity 2

Then you would have to include the primary key of Entity 1 to Entity 2.
So effectively Entity 2 would have a foreign key for Entity 1 ? What
would be the primary key for Entity 2 ? Would that include the foreign
key and its own Primary key together to form a multikeyed Primary key ?

Many thanks

[Ian]

Tommy wrote:

I'm new to database design and management. I'm presently taking a
course in this area. At the moment I just wanted to know when you have
the following relationship:

Entity 1 <---Relationship----> Entity 2 Integrity Contraint is 1 to N
from Entity 1 to Entity 2

Then you would have to include the primary key of Entity 1 to Entity 2.
So effectively Entity 2 would have a foreign key for Entity 1 ? What
would be the primary key for Entity 2 ? Would that include the foreign
key and its own Primary key together to form a multikeyed Primary key ?

Entity 2 may have a different attribute for its primary key, or, as you
suggest there may be a natural key that includes the attribute that is
the primary key of Entity 1. What is actually used depends on the
situation and the data modeler.