What lower bound of cardinality does full participation impl

What lower bound of cardinality does full participation imply? What does a min/max ratio of (1,1) between two entities imply?

Solution

Cardinality:Cardinality is min and max number of entity occurrence associated with one occurrence of the related entity. Cardinality types as

1 to 1 (one to one),

1 to many(one to many)

many to many

minimum represents the participation constraints,maximum stands for the cardinality ratio.

Min is the minimum number of Instances in one entity set that can be related to an instance of of Relationship.

The minimum can be between Zero and Maximum.

If the minimum is zero it implies that every instance of an entity does not have to participate in an instance of relationship. this is in effect means partial paticipation.

if minimum is grater than zero this implies full participation.ER Diagram with (min,max)ratio

if (min,max)of (0,1) means that each personnel may or may not married can only be married to atmost one personnel.

one to one realtionship: the relationship between guest and room.because a guest normally occupies one room. another example one person is responsible for one departmental budget

one to many: when one record is related to many records. this relationship referd to as one to many.

many to many:one record in a perticular record type can be related to many records in another record type and vice versa.example an album contains many songs at the same time , the song could be be included in different several albums