- What do you mean by binary and ternary relationship?
- What does binary relationship mean?
- What is a weak relationship?
- What is a weak relationship provide an example?
- How do you calculate degrees in a relationship?
- What hints would you look for to determine if a relationship is ternary?
- What is a one to many relationship in a database?
- What is weak key attribute?
- What do you mean by ternary relationship?
- What is cardinality of a relationship?
- What is types of relationship?
- What is weak attribute?
- What is a ternary relationship in ER diagram?
- What is degree of relationship type?
- What is the degree of a ternary relationship?
What do you mean by binary and ternary relationship?
Binary (two entities are involved in the relationship).
Ternary (three entities are involved in the relationship) N-ary (n entities involved in the relationship).
What does binary relationship mean?
A binary relationship is when two entities participate and is the most common relationship degree. For Example: A unary relationship is when both participants in the relationship are the same entity. For Example: Subjects may be prerequisites for other subjects.
What is a weak relationship?
Relationship strength. A weak or non-identifying relationship exists between two entities when the primary key of one of the related entities does not contain a primary key component of the other related entities.
What is a weak relationship provide an example?
A weak, or non-identifying, relationship exists if the primary key of the related entity does not contain a primary key component of the parent entity. Company database examples include: Customer(CustID, CustName)
How do you calculate degrees in a relationship?
The cousin with the lower number of generations determines the degree of cousinhood—first, second, third and so on. Then subtract the lower number of generations from the higher number to find out how many times removed the cousins are.
What hints would you look for to determine if a relationship is ternary?
What hints would you look for to determine if a relationship is ternary? You would be looking for the database tables with concatenated keys for multiple occurrences of primary keys to determine if a relationship is ternary (Rule 4).
What is a one to many relationship in a database?
In a relational database, a one-to-many relationship exists when one row in table A may be linked with many rows in table B, but one row in table B is linked to only one row in table A. It is important to note that a one-to-many relationship is not a property of the data, but rather of the relationship itself.
What is weak key attribute?
In a relational database, a weak entity is an entity that cannot be uniquely identified by its attributes alone; therefore, it must use a foreign key in conjunction with its attributes to create a primary key. The foreign key is typically a primary key of an entity it is related to.
What do you mean by ternary relationship?
A ternary relationship is an association among three entities. This type of relationship is required when binary relationships are not sufficient to accurately describe the semantics of the association. The ternary relationship construct is a single diamond connected to three entities as shown in Figure 2.3.
What is cardinality of a relationship?
Relationship cardinality represents the fact that each parent entity or table within a relationship is connected to a particular number of instances of the child entity or table.
What is types of relationship?
An interpersonal relationship refers to the association, connection, interaction and bond between two or more people. There are many different types of relationships. This section focuses on four types of relationships: Family relationships, Friendships, Acquaintanceships and Romantic relationships.
What is weak attribute?
weak. The weak attribute causes the declaration to be emitted as a weak symbol rather than a global. This is primarily useful in defining library functions which can be overridden in user code, though it can also be used with non-function declarations.
What is a ternary relationship in ER diagram?
A ternary relationship is when three entities participate in the relationship. For Example: The University might need to record which teachers taught which subjects in which courses.
What is degree of relationship type?
Degree of relationship is the number of entity sets that are participated (associated) in that relationship. That is, the number of entity sets that are connected through the relationship in question is called the degree of relationship.
What is the degree of a ternary relationship?
Ternary Relationship: a ternary relationship is a relationship of degree three. That is, a relationship that contains three participating entities. … The cardinality constraint of an entity in a ternary relationship is defined by a pair of two entity instances associated with the other single entity instance.