What is meant by maximum cardinality?
What is meant by maximum cardinality?
Maximum cardinality is defined as the maximum number of entity classes which are taking part in a relationship. There are three types of Maximum Cardinality: one-to-one, one-to-many, many-to-many.
Which of the following is a minimum cardinality?
Minimum cardinalities can be 0 or 1. A maximum cardinality indicates the number of instances of that entity that can be linked to at most one instance of the other entity. Maximum cardinalities can be 1 or N (many).
What are the possible values for maximum cardinality?
There are three types of maximum cardinality: one-to-one (1:1), one-to-many (1:N) and many-to-many (N:M). The minimum cardinality is the minimum number of entity instances that must participate in a relationship instance.
How many types of maximum cardinality exist in an ER model?
(T or F) 21) In an E-R model, the three types of maximum cardinality are 1:1, 1:N and N:M. (T or F) 22) In a 1:N relationship, the term parent refers to the N side of the relationship. (T or F) 23) A relationship’s minimum cardinality indicates whether or not an entity must participate in the relationship.
What is the minimum and maximum cardinality?
In 0:1 , 0 is the minimum cardinality, 1 is the maximum cardinality. In 1:n , 1 is the minimum cardinality, n is the maximum cardinality. A relationship with cardinality specified as 1:1 to 1:n is commonly referred to as 1 to n when focusing on the maximum cardinalities.
What is minimum cardinality in DBMS?
Minimum cardinality: minimum number of entity instances that must participate in a relationship. Each entity instance has a relationship with another entity instance: ▪ An EMPLOYEE has one BADGE ▪ A BADGE has an assigned EMPLOYEE.
What is maximum and minimum cardinality?
What is cardinality in DBMS?
In SQL (Structured Query Language), the term cardinality refers to the uniqueness of data values contained in a particular column (attribute) of a database table. The lower the cardinality, the more duplicated elements in a column.
What is the concept of cardinality?
: the number of elements in a given mathematical set.
What is minimum cardinality?
How are relationships classified by their maximum cardinality?
(T or F) 19) Relationships are classified by their cardinality. (T or F) 20) A relationship’s maximum cardinality indicates the maximum number of entities that can participate in the relationship. (T or F) 22) In a 1:N relationship, the term parent refers to the N side of the relationship.
How are cardinality and ordinality related in an entity?
Cardinality and ordinality Cardinality refers to the maximum number of times an instance in one entity can relate to instances of another entity. Ordinality, on the other hand, is the minimum number of times an instance in one entity can be associated with an instance in the related entity.
What does minimum cardinality mean in E-R model?
(T or F) 23) A relationship’s minimum cardinality indicates whether or not an entity must participate in the relationship. (T or F) 24) In an E-R model, the three types of minimum cardinality are mandatory, optional and indeterminate.
What is the minimum cardinality of a weak entity?
(T or F) 29) All weak entities must have a minimum cardinality of 1 on the entity on which it depends. (T or F) 30) Subtype entities contain only attributes unique to the subtypes. (T or F) 31) An attribute that determines which subtype is appropriate is called a discriminator.